xpt's questions

I'm trying to copy my Launchpad package to the new Noble repo,

• I first tried to copy binary package but failed with:

Target series: Noble
my-pkg 1.1.0-1 in jammy (binaries conflicting with the existing ones)

• I then tried to copy source package but still failed:

Target series: Noble
my-pkg 1.1.0-1 in focal (same version already has published binaries in the destination archive)

This is wrong, as the first copy failed, and I don't see it when I tried to "Delete package" myself.

I think this is more or less a launchpad internal error, but is there anything I can do about it please?

I'm a bit confused about the Debian package version orders.

Take a look at the following two Debian package versions, how come the first is <= than the second?

0-emacs-29.1.90~202401142128~ubuntu20.04.1
0-emacs-28.3-rc1~202302201437~ubuntu20.04.1

I'm thinking that 29 > 28 so the first should be more recent, no?

First time using KUbuntu (22.04.1 LTS); used to use Mate & LUbuntu before, which my fcitx Chinese input had been working fine. However,

With KUbuntu 22.04.1 LTS, my fcitx Chinese input is not working out of the box -- I simply cannot get it triggered.

Here is proof that my fcitx Chinese input's installation is fine.

• On my KUbuntu 22.04.1 starts up, there are three fcitx related processes (identified by ps -eaf --width 200 | grep [f]citx):
  • /usr/bin/dbus-daemon --syslog --fork --print-pid 5 --print-address 7 --config-file /usr/share/fcitx/dbus/daemon.conf
  • /usr/bin/fcitx-dbus-watcher unix:abstract=/tmp/dbus-tW4A6FKmPk,guid=e64c862b67b86932863ee75863f14a15 5504
  • fcitx
• If I kill them all one by one, then start fcitx again manually under
  LANG=zh_CN.utf8 urxvt -ls &
  then everything is fine. Triggering hotkey is working again.

UPDATE: -- There is also an IBus Pannel icon on my KUbuntu 22.04.1 taskbar when it starts up, and I have to quit it manually each time after boot.

So it makes me suspect that the fcitx started by my KDE has the wrong setting, which what I'm trying to fix. (My normal (desktop) work environment is English, using LANG=C. The fcitx is only used for/with any applications that started under/with the LANG='zh_CN.utf8' environment, like rxvt-unicode, chrome, etc)

How to fix it? please help.

$ im-config -m
default
missing
ibus

ibus

$ LANG=C im-config -m
default
missing
ibus

ibus

$ LANG=C im-config -m | tail -3 | hexdump -C
00000000  69 62 75 73 0a 0a 69 62  75 73 0a                 |ibus..ibus.|

$ LANG='zh_CN.utf8' im-config -m
default
missing
ibus
fcitx5
ibus

Final UPDATE:

I tracked down the root reason why I have both ibus and fcitx installed. Here is why it is a bad idea first:

The reason that I have both input methods installed is because of the zoom that I need to use, and from these two pages, I can see that such requirement is really unnecessary:

1. Annoying ibus dependency in zoom .deb files
2. Zoom Debian Linux package requires ibus even on KDE and XFCE

Here are a few quotes:

• The .deb files for downloading zoom come with ibus in the “Depends:” field. That’s a problem for many Debian/Ubuntu users, and I’ll try to explain why.
• Needless to say I’m very disappointed at Zoom’s way to respond to my request so far.
• I’m working with the maintenance of a tool (im-config) used in Debian and Ubuntu to facilitate the configuration of input methods, e.g. IBus. It’s in that role I have received complaints about the ibus dependency in the Zoom .deb file, and it’s in that role I’m here.
• This is [email protected] (my official Debian contact address) who is a core member of maintaining ibus package for Debian. (Gunnar is another core member too. He is heavily involved in Ubuntu side.)
• His request is not a mere “user request”. This should be considered a demand by the GNU/Linux distributions to ZOOM.
• If Zoom provide package for Debian/Ubuntu (deb-packages) with technically sound contents, ZOOM should listen to us.
• Any updates on this? Just installed zoom and got this too. This dependency is annoying and worthless
• This excuse for “remote control on a remote machine” is pathetically lacking understanding how “Depends:” field should be used for Debian package. This should be used only for packages which is required under all installation environment. Doing this for a particular environment is considered rude engineering.
• I’m a Debian Developer and hence familiar with the conventions and requirements for Debian packages, aka “.deb” files. As currently defined, the way that the Zoom Debian packages use relationship fields (such as Depends:) violate the Debian packaging policy, outlined here: 7. Declaring relationships between packages — Debian Policy Manual v4.6.1.1

However all the requests fall into deaf ears and 1 month later, "This topic was automatically closed 30 days after the last reply. New replies are no longer allowed." and that results comment from link 2:

• The Zoom Debian Linux package is requiring ibus. But ibus is part of GNOME desktop. So installing zoom_amd64.deb under KDE Plasma breaks keyboard support due to ibus and related dependencies which do not work under KDE.
• Yep, I am doing a new install of Zoom and suddenly get dependencies on ibus, libegl1-mesa, libxcb, python3-ibus, ibus-gtk and a few others. I am using a few month old Linux distro so there should be NO reason Zoom won't install. I don't need ibus, it will ruin my setup. This is just crazy. . . When a multi-billion dollar goliath like Zoom hires sub-par developers to package their software, arguably the most important job in a software firm - they deserve to fail! I read the Support forums on this same topic and the absolute failure of support staff to understand the weight of this problem was unbelievable. The Debian Maintainers of ibus made posts to try and help out, but Zoom staff ignored them. I consider this a massive failure from Zoom and a smack in the face for Linux users everywhere.

I used to add contrib & non-free to my apt sources, but found they're gone from jammy:

$ sudo apt update
W: Skipping acquire of configured file 'contrib/binary-amd64/Packages' as repository 'http://archive.ubuntu.com/ubuntu jammy InRelease' doesn't have the component 'contrib' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'non-free/binary-amd64/Packages' as repository 'http://archive.ubuntu.com/ubuntu jammy InRelease' doesn't have the component 'non-free' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'contrib/binary-amd64/Packages' as repository 'http://archive.ubuntu.com/ubuntu jammy-updates InRelease' doesn't have the component 'contrib' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'non-free/binary-amd64/Packages' as repository 'http://archive.ubuntu.com/ubuntu jammy-updates InRelease' doesn't have the component 'non-free' (component misspelt in sources.list?)

Then, how to fix common problems like:

E: Package 'rar' has no installation candidate
E: Package 'unrar' has no installation candidate

$ cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu/ jammy main contrib non-free restricted universe
deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe
deb http://archive.ubuntu.com/ubuntu/ jammy-updates main contrib non-free restricted universe

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.1 LTS
Release:        22.04
Codename:       jammy

Following up on Making fcitx work under Lubuntu 18.04

I've got all the fcitx packages I believe:

 fcitx_1:4.2.9.8-3
 fcitx-bin_1:4.2.9.8-3
 fcitx-config-common_0.4.10-3
 fcitx-config-gtk_0.4.10-3
 fcitx-data_1:4.2.9.8-3
 fcitx-frontend-all_1:4.2.9.8-3
 fcitx-frontend-gtk2_1:4.2.9.8-3
 fcitx-frontend-gtk3_1:4.2.9.8-3
 fcitx-frontend-qt5:amd64_1.2.5-1ubuntu2
 fcitx-googlepinyin:amd64_0.1.6-4build1
 fcitx-module-dbus_1:4.2.9.8-3
 fcitx-module-kimpanel_1:4.2.9.8-3
 fcitx-module-lua_1:4.2.9.8-3
 fcitx-module-x11_1:4.2.9.8-3
 fcitx-modules_1:4.2.9.8-3
 fcitx-ui-classic_1:4.2.9.8-3
 fcitx5-module-quickphrase-editor:amd64_1.2.5-1ubuntu2
 libfcitx-config4:amd64_1:4.2.9.8-3
 libfcitx-core0:amd64_1:4.2.9.8-3
 libfcitx-gclient1:amd64_1:4.2.9.8-3
 libfcitx-qt5-1:amd64_1.2.5-1ubuntu2
 libfcitx-qt5-data_1.2.5-1ubuntu2
 libfcitx-utils0:amd64_1:4.2.9.8-3

But my fcitx config is still showing empty methods:

I've tried both fcitx-config-gtk3 and fcitx-configtool. Both showing empty methods.

Consequently using hot key trying to invoke/trigger fcitx has no effect at all.

Anybody can help?

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 21.10
Release:        21.10
Codename:       impish

Following up with Copy/paste and drag&drop not working in VMware machine with Ubuntu,

For any Live Linux system (Ubuntu, KUbuntu, LUbuntu, etc), I don't think copy/paste text can be working out of the box. However, from the above answer, the solution is simple, as far as normal Linux system is concerned, just to install open-vm-tools and open-vm-tools-desktop.

However, the last step from the above answer is,

Reboot the VM, after the reboot copy/paste and drag/drop will work!

That's problematic for a Live Linux system, because if I reboot, I'll loose everything I've just done.

So what's the magic of the reboot? Can I have the copy/paste functionality without a system reboot?

• I did a minimum net install, but my new system is not starting the network automatically -- No IP address with my eth0 device.
• I installed dhclient package myself but that doesn't help. I thought it should have been taken care of by the post-install of the dhclient package.
• Searching for the answer myself, I found this page, hinting that I have to write such systemd unit for myself.
• If so, I have to first understand what's systemd unit activate vs enable, whereas previously in init5, all I need to do is to install a service package and its post-install will take care of enabling the service itself.

All these have been way too complicated than it should, I believe. Somebody help please.

UPDATE:

OK, maybe the reason is that this is a minimum net install, and I don't have all those things required. Here is more info:

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 00:0c:29:56:d8:4c brd ff:ff:ff:ff:ff:ff
    altname enp2s1
    altname ens33

$ ls /etc/netplan
ls: cannot access '/etc/netplan': No such file or directory

$ sudo service NetworkManager status
Unit NetworkManager.service could not be found.

$ ls /usr/lib/systemd/system/dhcpcd.service
ls: cannot access '/usr/lib/systemd/system/dhcpcd.service': No such file or directory

But still, if I run dhclient myself manually, I will get IP under such minimum install. I.e., the NetworkManager is not absolutely necessary, I hope. And I hope there is a fix for situation like this, whether using dhcpcd or dhclient.

If I have two files in /etc/fonts/conf.d/.

One being:

<fontconfig>
<alias>
 <family>sans-serif</family>
 <prefer>
   <family>Noto Color Emoji</family>
 </prefer>
</alias>
</fontconfig>

And the other one being:

<fontconfig>
<alias>
 <family>sans-serif</family>
 <prefer>
   <family>Noto Emoji</family>
 </prefer>
</alias>
</fontconfig>

What would the outcome be after they are both read in?

Reason behind the question --
I have a huge and messy font-selection file. If I can somehow build the font selection from files step by step, that'll be hugely tidy up my messy font-selection file. So,

Using the Noto Emoji as an example, how can I build my font selection step by step so that Noto Color Emoji is the default and Noto Emoji is the fallback?

Following up on How do you set the timezone for crontab?, where CentOS 7 distro with cronie 1.4 has CRON_TZ environment variable, but Ubuntu 20.04 LTS' crontab(5) manpage still doesn't have CRON_TZ. It says:

"It currently does not support per-user timezones."

I need to setup cron job on a remote server (in Europe, shared, not mine), which has different daylight saving time schedule than America.

I just discovered that chromium is released as a snap package in my Ubuntu 20.04, and I'd like to know what else are like this. So,

How can I tell which packages come from snap? I.e., I want to have a list of packages that on trying to install using APT actually installs Snaps.

I've always been a GTK camp user but switched to Kubuntu just recently (for 20.04). But I haven't found where Kubuntu store its networking configuration files yet. I've looked at every file that I know of, e.g.:

$ cat /etc/netplan/01-network-manager-all.yaml
# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

$ dir /etc/NetworkManager/system-connections/
total 0

$ cat /etc/network/interfaces
cat: /etc/network/interfaces: No such file or directory

The reason I'm asking is that I want to use Static IP for my Kubuntu, but I don't know where do I start with. thx.

The docs says, that The json1 extension is a loadable extension for sqlite3, and the loadable extensions need to be compiled as shared libraries (source).

I searched a lot and I don't know how to enable them. I found that

• the compiled shared libraries might be provided by libsqlite3-mod-impexp
• many article tells how to install libsqlite3-mod-impexp (just apt install actually), but none mentioned what's next, to enable the loadable extension, and use it.

Any detailed steps, and sample verification commands appreciated.

I need to use the json1 extension for sqlite3, i.e. using json in where clauses when invoking sqlite3 command from command line.

I'm trying to make fcitx work under Lubuntu.

Here are problems I'm facing:

• fcitx is not auto-started with Lubuntu. I checked the lxsession auto-start configuration, and found that fcitx is not an option there.
• I can launch the fcitx applet from the menu with System Tools ‣ Fcitx, but that has two more problems,
  • I still cannot turn my google pinyin input on using keyboard
  • If I turn my google pinyin on using its pop-up menu, it will freeze the whole system. Tried and verified many time when using the leafpad, and even the fcitx configuration program itself -- start leafpad or fcitx configuration program, then left click Fcitx icon trying to bring up its pop-up menu, the whole system will freeze.

This is Lubuntu 18.04.02. I am able to make fcitx work under Mate 18.04, so I think it is a Lubuntu specific problem.

Is there a solution?

The situation is, for a simple docker command:

docker run -d -p 3128:3128 my_squid_container

it works fine within my home. However, when using the same Docker container in the Azure Ubuntu server, I get:

$ curl --proxy http://localhost:3128 http://google.com
curl: (56) Recv failure: Connection reset by peer

After a heck of troubleshooting, it turns out that the Docker default network (of the the Azure Ubuntu server) is blocked, by some kind of firewall I suppose, but I couldn't figure out / confirm the real source.

There has been suspicious of UFW, but I saw:

• UFW not blocking connections to docker instance
• Uncomplicated Firewall (UFW) is not blocking anything when using Docker

Moreover, my UFW status is inactive:

$ sudo ufw status
Status: inactive

So is it true that UFW is blocking my Docker network connection?

Trying to answer it myself, I checked How do I know if my firewall is on?, and here is the relevant information that might help:

$ sudo ufw status
Status: inactive

$ sudo iptables -v -x -n -L
Chain INPUT (policy ACCEPT 186 packets, 67614 bytes)
    pkts      bytes target     prot opt in     out     source               destination

Chain FORWARD (policy DROP 0 packets, 0 bytes)
    pkts      bytes target     prot opt in     out     source               destination
   83321 462267984 DOCKER-USER  all  --  *      *       0.0.0.0/0            0.0.0.0/0
   83321 462267984 DOCKER-ISOLATION-STAGE-1  all  --  *      *       0.0.0.0/0            0.0.0.0/0
       0        0 ACCEPT     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
       0        0 DOCKER     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0
       0        0 ACCEPT     all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0
       0        0 ACCEPT     all  --  docker0 docker0  0.0.0.0/0            0.0.0.0/0

Chain OUTPUT (policy ACCEPT 244 packets, 55542 bytes)
    pkts      bytes target     prot opt in     out     source               destination

Chain DOCKER (1 references)
    pkts      bytes target     prot opt in     out     source               destination
       0        0 ACCEPT     tcp  --  !docker0 docker0  0.0.0.0/0            172.17.0.2           tcp dpt:3128

Chain DOCKER-ISOLATION-STAGE-1 (1 references)
    pkts      bytes target     prot opt in     out     source               destination
       0        0 DOCKER-ISOLATION-STAGE-2  all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0
   83729 466271977 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0

Chain DOCKER-ISOLATION-STAGE-2 (1 references)
    pkts      bytes target     prot opt in     out     source               destination
       0        0 DROP       all  --  *      docker0  0.0.0.0/0            0.0.0.0/0
   44567 231463994 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0

Chain DOCKER-USER (1 references)
    pkts      bytes target     prot opt in     out     source               destination
  245275 2311152470 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0


# NAT setting

$ sudo iptables -t nat -v -x -n -L
Chain PREROUTING (policy ACCEPT 60056 packets, 2443714 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
   80820  3320327 DOCKER     all  --  *      *       0.0.0.0/0            0.0.0.0/0            ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 60053 packets, 2443525 bytes)
    pkts      bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 217217 packets, 13050882 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
       0        0 DOCKER     all  --  *      *       0.0.0.0/0           !127.0.0.0/8          ADDRTYPE match dst-type LOCAL

Chain POSTROUTING (policy ACCEPT 217217 packets, 13050882 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
       3      189 MASQUERADE  all  --  *      !docker0  172.17.0.0/16        0.0.0.0/0           
       0        0 MASQUERADE  tcp  --  *      *       172.17.0.2           172.17.0.2           tcp dpt:3128

Chain DOCKER (2 references)
    pkts      bytes target     prot opt in     out     source               destination         
       0        0 RETURN     all  --  docker0 *       0.0.0.0/0            0.0.0.0/0           
       0        0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            0.0.0.0/0            tcp dpt:3128 to:172.17.0.2:3128

I do have fail2ban installed and running BTW, but I doubt that it is blocking my internal port usage.

All in all, who is blocking my docker default network? Thx.

UPDATE2:

The docker default network was blocked initially, but suddenly it worked for no reason, as explained below, but now docker network is blocked again. Good that I've listed the output of the iptable, including the NAT setting, so I can do a comparison of then and now. And it turns out that for the above two iptable commands, their rules are still the same -- the output only differ with packets & bytes numbers.

• iptables -v -x -n -L: https://paste.pics/7918fba5e040d63cfb0fc28d9f233835
• iptables -t nat -v -x -n -L: https://paste.pics/ada83fb1ae4e933b2511a827094ce788

so UFW should be ruled out from the cause. If confirmed I'll remove its tag.

UPDATE: (it suddenly worked for no reason for a very short while)

I don't know what happened, but I was about to give more info, and this is what I get, word for word, nothing more nothing less:

$ curl --proxy http://localhost:3128 https://google.com
curl: (56) Proxy CONNECT aborted

$ curl -v --proxy http://localhost:3128 http://google.com
* Rebuilt URL to: http://google.com/
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 3128 (#0)
> GET http://google.com/ HTTP/1.1
> Host: google.com
> User-Agent: curl/7.58.0
> Accept: */*
> Proxy-Connection: Keep-Alive
>
< HTTP/1.1 301 Moved Permanently
< Location: http://www.google.com/
< Content-Type: text/html; charset=UTF-8
< Date: Sat, 10 Aug 2019 18:06:51 GMT
< Expires: Mon, 09 Sep 2019 18:06:51 GMT
< Cache-Control: public, max-age=2592000
< Server: gws
< Content-Length: 219
< X-XSS-Protection: 0
< X-Frame-Options: SAMEORIGIN
< X-Cache: MISS from 5c83ae696b4c
< X-Cache-Lookup: MISS from 5c83ae696b4c:3128
< Via: 1.1 5c83ae696b4c (squid/4.8)
< Connection: keep-alive
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="http://www.google.com/">here</A>.
</BODY></HTML>
* Connection #0 to host localhost left intact

$ curl --proxy http://localhost:3128 https://google.com
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="https://www.google.com/">here</A>.
</BODY></HTML>

Honestly, I don't know what's going on, and you can see that it didn't work before, even today, and it is suddenly working right before my eyes.

So let me include back what I posted in OP (although no further details than that), and what happened before:

$ sudo iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy DROP)
target     prot opt source               destination
DOCKER-USER  all  --  anywhere             anywhere
DOCKER-ISOLATION-STAGE-1  all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
DOCKER     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
DOCKER     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain DOCKER (2 references)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             172.19.0.2           tcp dpt:3128

Chain DOCKER-ISOLATION-STAGE-1 (1 references)
target     prot opt source               destination
DOCKER-ISOLATION-STAGE-2  all  --  anywhere             anywhere
DOCKER-ISOLATION-STAGE-2  all  --  anywhere             anywhere
RETURN     all  --  anywhere             anywhere

Chain DOCKER-ISOLATION-STAGE-2 (2 references)
target     prot opt source               destination
DROP       all  --  anywhere             anywhere
DROP       all  --  anywhere             anywhere
RETURN     all  --  anywhere             anywhere

Chain DOCKER-USER (1 references)
target     prot opt source               destination
RETURN     all  --  anywhere             anywhere

$ curl -v --proxy http://localhost:3128 http://google.com
* Rebuilt URL to: http://google.com/
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 3128 (#0)
> GET http://google.com/ HTTP/1.1
> Host: google.com
> User-Agent: curl/7.58.0
> Accept: */*
> Proxy-Connection: Keep-Alive
>
* Recv failure: Connection reset by peer
* stopped the pause stream!
* Closing connection 0
curl: (56) Recv failure: Connection reset by peer

From "Do we need to reboot after adding an user to sudoers?", it is apparent that restarting Sudo Service is necessary, or reboot. However the recommended way, which works for Ubuntu 14.04, is no longer working for Ubuntu 18+:

$ sudo service sudo restart
Failed to restart sudo.service: Unit sudo.service is masked.

Solution?

Following up on Install Grub2 to PBR, and opening a new question to provide link to boot-info-summary, as per @mook765:

http://paste.ubuntu.com/p/SnT6Tcdmqk/

Here is again the problem:

% grub-install /dev/sdc5
Installing for i386-pc platform.
grub-install: warning: File system `ext2' doesn't support embedding.
grub-install: warning: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and their use is discouraged..
grub-install: error: will not proceed with blocklists

I.e., grub-install refuses to proceed with blocklists, saying "File system 'ext2' doesn't support embedding". However, mine is not an ext2 file-system but ext4, and it does NOT need fsck:

$ mount | grep /dev/sdc5
/dev/sdc5 on /mnt/osp type ext4 (rw,noatime,nodiratime,data=ordered)

% umount /dev/sdc5
umount: /dev/sdc5: not mounted.

% fsck.ext4 /dev/sdc5
e2fsck 1.44.1 (24-Mar-2018)
osp: clean, 115049/513072 files, 897251/2048287 blocks

and for your convenient, here is the relevant part from the boot-info-summary:

sdc5: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  Grub2 (v1.99-2.00)
    Boot sector info:  Grub2 (v1.99-2.00) is installed in the boot sector of 
                       sdc5 and looks at sector 34172346 of the same hard 
                       drive for core.img, but core.img can not be found at 
                       this location.
    Operating System:  Ubuntu 18.04.2 LTS
    Boot files:        /boot/grub/grub.cfg /etc/fstab 
                       /boot/extlinux/extlinux.conf 
                       /boot/grub/i386-pc/core.img

AMEND:

Alright, let me explain my configuration a bit.

• I don't use lilo to boot my system. The only reason I put lilo in mbr is that, it has the advantage of being able to boot directly from extended partition, instead of from prime partitions only.
• Yes I have 4 MBRs, i.e., 4 HDs, but all HD are setup the same -- it will be booted from the active partition, show as "*" in fdisk -l output, thanks to the lilo in mbr. In fact any normal MBR will do as all my active partition are prime partitions, not extended partition. But I just kept my option open.
• The active partition, of any HD, is booted by extlinux. From there I chainload whatever I want to boot, from its boot menu.
• The normal Linux partition are booted by extlinux as well, but somehow I wasn't able to make /dev/sdc5 booted by extlinux, so I switched to grub2, and it had been booting fine before.
• The problem started when I try to make a USB partition bootalble, the "install the grub2 as the boot-loader from OS in partition-B to OS on partition-A" thing in my previous question.
• Now neither partition-B nor partition-A are bootable any more.
• For full disclosure, both partition-B and partition-A are restored from a LUbuntu system that I carefully installed and trimmed. This "restored" is the main reason I wasn't able to make it bootable via extlinux, I suspect, but can't prove.
• Legacy grub is a staled partition/OS that I have't touch for years, even 10+ years, however,
• the grub4dos is the one I newly setup on my USB disk. It is bootable, and it allows me to chain boot into anything that I want, with simple syntax that I understand well. I.e., it has nothing to do with how my current system boot, as I may detach it at any moment.

How to remove system locales, as oppose to package locales as asked in How to remove unnecessary locales??

I'm getting the following errors recently:

locale: Cannot set LC_ALL to default locale: No such file or directory

The only en locale I have in my system:

$ grep -r en /var/lib/locales/supported.d/*
/var/lib/locales/supported.d/local: en_US ISO-8859-1
/var/lib/locales/supported.d/local: en_US.UTF-8 UTF-8

$ locale -a | grep en
en_US
en_US.iso88591
en_US.utf8

but not en, as complained by perl:

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
        LANGUAGE = "",
        LC_ALL = (unset),
        LC_MEASUREMENT = "en",
        LC_PAPER = "en",
        LC_MONETARY = "en",
        LC_NAME = "en",
        LC_ADDRESS = "en",
        LC_NUMERIC = "en",
        LC_TELEPHONE = "en",
        LC_IDENTIFICATION = "en",
        LC_TIME = "en",
        LANG = "C"

So I add the locale en by:

% locale-gen en
Generating locales (this might take a while)...
  en_AG.UTF-8... done
  en_AU.UTF-8... done
  en_BW.UTF-8... done
  en_CA.UTF-8... done
  en_DK.UTF-8...^C

I don't want any of above locales (only en_US), but now I can't get rid of them -- I followed the steps in https://serverfault.com/questions/394610/remove-a-locale-in-ubuntu

But when it comes to the last step, I'm still getting:

% locale-gen
Generating locales (this might take a while)...
  en_AG.UTF-8... done
  en_AU.UTF-8... done
  en_BW.UTF-8... done
  en_CA.UTF-8... done
  en_DK.UTF-8...^C

How to remove all above locales and keep only en_US?

Conclusion & Supplement

Thanks to Gunnar's answer, it is indeed caused by entries in /etc/locale.gen, for those extra locales. Just FTR, this is what locale-gen en has changed in /etc/locale.gen:

$ sed '/^#/d; /en/p;' /etc/locale.gen


en_AG UTF-8
en_AG UTF-8
en_AU.UTF-8 UTF-8
en_AU.UTF-8 UTF-8
en_BW.UTF-8 UTF-8
en_BW.UTF-8 UTF-8
en_CA.UTF-8 UTF-8
en_CA.UTF-8 UTF-8
en_DK.UTF-8 UTF-8
en_DK.UTF-8 UTF-8
en_GB.UTF-8 UTF-8
en_GB.UTF-8 UTF-8
en_HK.UTF-8 UTF-8
en_HK.UTF-8 UTF-8
en_IE.UTF-8 UTF-8
en_IE.UTF-8 UTF-8
en_IL UTF-8
en_IL UTF-8
en_IN UTF-8
en_IN UTF-8
en_NG UTF-8
en_NG UTF-8
en_NZ.UTF-8 UTF-8
en_NZ.UTF-8 UTF-8
en_PH.UTF-8 UTF-8
en_PH.UTF-8 UTF-8
en_SC.UTF-8 UTF-8
en_SC.UTF-8 UTF-8
en_SG.UTF-8 UTF-8
en_SG.UTF-8 UTF-8
en_US.UTF-8 UTF-8
en_US.UTF-8 UTF-8
en_ZA.UTF-8 UTF-8
en_ZA.UTF-8 UTF-8
en_ZM UTF-8
en_ZM UTF-8
en_ZW.UTF-8 UTF-8
en_ZW.UTF-8 UTF-8

As a comparison, here is what the default looks like (i.e., without any of the above extra locales):

$ sed '/^#/d;' /etc/locale.gen; echo ---


---

debootstrap is a tool which will install a Debian/Ubuntu base system into a subdirectory of another, already installed system.

The installation log ends like this:

. . . 
I: Validating xxd 2:8.1.0320-1ubuntu3
I: Validating xz-utils 5.2.4-1
I: Validating zlib1g 1:1.2.11.dfsg-1ubuntu2
I: Chosen extractor for .deb packages: dpkg-deb
I: Extracting base-files...

So it seems to me that the only package debootstrap extracts is base-files, right?

Is there any way for debootstrap to extract/install more packages? Especially, I found that debootstrap doesn't even install linux kernel at all. Can I somehow let debootstrap to install linux kernel as well?

Looks to me that my systemd starts dnsmasq before starting network manager. How can I confirm this? How can I force systemd starts dnsmasq after starting network manager?

Reason behind this is, as explained in NetworkManager not updating /var/run/networkmanager/resolv.conf,

• I'm using dnsmasq as my LAN DNS server, and
• I defined my two IP addresses in NetworkManager.

When my system started my dnsmasq is not working, and I found that the reason is it is not listening to my two IP addresses at all. Only after restarting it, it started to listen to my two IP addresses:

$ lsof -i tcp:53
COMMAND   PID            USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
systemd-r 544 systemd-resolve   13u  IPv4  18667      0t0  TCP 127.0.0.53:domain (LISTEN)
dnsmasq   793         dnsmasq    5u  IPv4  23719      0t0  TCP localhost.my.box.name:domain (LISTEN)
dnsmasq   793         dnsmasq    7u  IPv6  23721      0t0  TCP ip6-localhost:domain (LISTEN)

/etc/init.d/dnsmasq restart
[ ok ] Restarting dnsmasq (via systemctl): dnsmasq.service.

$ lsof -i tcp:53
COMMAND     PID            USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
systemd-r   544 systemd-resolve   13u  IPv4  18667      0t0  TCP 127.0.0.53:domain (LISTEN)
dnsmasq   17895         dnsmasq    5u  IPv4 601091      0t0  TCP 192.168.0.10:domain (LISTEN)
dnsmasq   17895         dnsmasq    7u  IPv4 601093      0t0  TCP 192.168.0.11:domain (LISTEN)
dnsmasq   17895         dnsmasq    9u  IPv4 601095      0t0  TCP localhost...

$ lsb_release -a 
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.1 LTS
Release:        18.04
Codename:       bionic

# my systemd is not the latest but I think that shouldn't matter:
$ apt-cache policy systemd
systemd:
  Installed: 237-3ubuntu10
  Candidate: 237-3ubuntu10.9
  Version table:
     237-3ubuntu10.9 500
        500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
 *** 237-3ubuntu10 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

Update:

@heynnema, Thanks for the systemd-analyze --no-pager blame, I've confirmed that the start order is as expected

NetworkManager -> systemd-resolved -> dnsmasq.

So indeed, it is about dnsmasq and systemd-resolved stepping on each others toes. I've added DNSStubListener=no since. I have two following up questions now.

• Why it is OK for dnsmasq restart to work just fine? Its working fine gave me the impression that it is OK to have them both working.
• Actually, I used systemctl stop systemd-resolved and systemctl disable systemd-resolved to completely disable systemd-resolved, instead of just stopping its listener previously. I don't know why it does not persist over reboot.

Following How to disable systemd-resolved and resolve DNS with dnsmasq?

However, I followed it as much as I could, but still wasn't able to properly replace systemd-resolved with dnsmasq --

If i put dns=dnsmasq under [main] in /etc/NetworkManager/NetworkManager.conf, then the nameserver in my /etc/resolv.conf will be my ISP's, not my dnsmasq. If removing it, then the nameserver in my /etc/resolv.conf will remain to be systemd-resolved's, i.e., 127.0.0.53

So all in all, how to properly use dnsmasq as system DNS service?

• I've removed resolvconf, and now the question is,
• how to replace systemd-resolved with dnsmasq?

PS.

$ lsb_release -a 
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.1 LTS
Release:        18.04
Codename:       bionic

UPDATE:

I've actually tried two times, with the latest attempt from a fresh Lubuntu 18.04.2 LTS installation, and both cases did not work. By "did not work" I meant I can see dnsmasq is listening on ':53' via netstat, but dig cnn.com and/or any DNS query times out.

Here is the updated info. Note that I've reverted my changes and am now back to using systemd-resolved. So results like grep -i stub /etc/systemd/resolved.conf reflect my current stage (back to systemd-resolved).

$ dpkg -l '*dnsmasq*'
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                Version        Architecture   Description
+++-===================-==============-==============-===========================================
ii  dnsmasq             2.79-1         all            Small caching DNS proxy and DHCP/TFTP serve
ii  dnsmasq-base        2.79-1         amd64          Small caching DNS proxy and DHCP/TFTP serve
un  dnsmasq-base-lua    <none>         <none>         (no description available)
ii  dnsmasq-utils       2.79-1         amd64          Utilities for manipulating DHCP leases

$ ls -al /etc/resolv.conf
lrwxrwxrwx 1 root root 35 2019-07-14 22:07 /etc/resolv.conf -> /var/run/NetworkManager/resolv.conf

$ grep -i stub /etc/systemd/resolved.conf
#DNSStubListener=yes

$ cat /etc/NetworkManager/NetworkManager.conf
[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

[device]
wifi.scan-rand-mac-address=no

# I've removed `resolvconf`:
$ dpkg -l '*resolvconf*'
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                Version        Architecture   Description
+++-===================-==============-==============-===========================================
un  resolvconf          <none>         <none>         (no description available)

$ sudo ls /run/resolvconf/resolv.conf
ls: cannot access '/run/resolvconf/resolv.conf': No such file or directory

UPDATE2:

I now think I know what went wrong -- after the change (following all the steps in the answer), I checked the content of /etc/resolv.conf, and found its content remains the same. I.e., still having nameserver 127.0.0.53.

Now I recall that nameserver 127.0.0.53 is for systemd-resolved, whereas for dnsmasq, it should be nameserver 127.0.0.1. That's why all DNS queries are timing out.

I.e., there is one step missing from the answer, which is to change nameserver to 127.0.0.1 in /etc/resolv.conf, which I don't know how.