pauljohn32's questions

Can I "wake up" an idle Xrdp connection in the "black screen of death" state by logging in from another user account and doing some code magic?

Here's the reason I ask.

For work I have to use Windows 10. Bummer, I know. But I got permission to install WSL (subsystem for Linux). I'm able to get many X11 apps running with an X server. I've tried WSL1 and 2. WSL2 has quite a few conflicts with corporate VPN, so I'm staying with WSL1.

I found several posts about launching an Xrdp session from WSL and connecting to it with the Windows Remote Desktop Client on the same system (Linux on Windows, Running WSL Gui on Windows) The setup is not too easy, but I got an XFCE4 session working and it is pretty good!

However, I run into the infamous "black screen" of death now and then. When you leave an Xrdp session idle, then when you return, after giving a password, then the Xrdp screen is black. Following suggestions that blame the desktop for 'going to sleep' via screen/power saver, I've disabled all of the screen savers and power managers. The black screen does not happen very often. But if I forget to log out of the RDP session and leave it overnight, I have BSOD in the morning.

After trying many fixes, the BSOD seems unavoidable. I've tried this with WSL sessions based on Ubuntu 20.04 and 20.10, I don't think there's a fix. Something triggers an flock or powers off the monitor.

But I have a new idea today!

I created another user account in WSL. When first account is in BSOD, I can log in with other account. I can su as the user whose account is in black screen. Tell me some way to kick-start the session from there, please!

I have a Dell Precision 7300 and the touchpad worked fine with kernel 5.8.0-38, but the update to 5.8.0-45 caused the touchpad to quit working. The same touchpad problem also exists in 5.8.0-44.

When in 5.8.0-45, I can insert a USB mouse and it works fine.

I've been digging around in logs to try to figure out what's going on, but as far as I can tell no device is found.

Have you seen a problem like this? Have you suggestions?

I've got 2 packages with the version locked because the new ones are not compatible with other programs I use. This prevents the Ubuntu distribution upgrade from even trying to do its work. Observe:

$ sudo apt-get update
Hit:1 https://rweb.crmda.ku.edu/cran/bin/linux/ubuntu bionic-cran35/ InRelease
Hit:2 http://archive.canonical.com/ubuntu cosmic InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu cosmic InRelease
Hit:4 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:5 http://us.archive.ubuntu.com/ubuntu cosmic-backports InRelease
Hit:6 http://us.archive.ubuntu.com/ubuntu cosmic-updates InRelease
Hit:7 http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu cosmic InRelease
Hit:8 http://security.ubuntu.com/ubuntu cosmic-security InRelease
Hit:9 http://ppa.launchpad.net/unit193/encryption/ubuntu cosmic InRelease
Reading package lists... Done

$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
  git-lfs thunderbird
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.

$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.

The only workaround I can see is to allow the updates to happen with git-lfs and thunderbird, then do the upgrade, and then install the old versions of those programs. Seems more tedious than it should be.

Other ideas?

When I run programs that use GTK from the terminal, I almost always see warnings (sometimes many warnings) like this:

Gtk-Message: 09:18:04.593: Failed to load module "atk-bridge"

This happens with evince and many others. How can these warnings be silenced?

I've had a comedy of video errors that all trace back to a kernel upgrade in Ubuntu 18.10 cosmic. The kernel 4.18.0.11.12 causes trouble, well, in every conceivable way and I can't quite understand why it works for anybody.

In case you have "black screen of death" at various phases, my suggestion is to resist advice to fiddle a lot with config for video or display manager. Instead, boot with older kernel to see if problems disappear. Hardest part for most users will be figuring how to make Ubuntu show a grub menu to choose a kernel (they've made that tricky, but have instructions: https://wiki.ubuntu.com/RecoveryMode).

The symptoms of the problem revolve around

1. Black screen of death with message about rejection of PKS keys
2. Unable to start display manager (gdm3 or lightdm)
3. External monitors not recognized (by desktop programs or xrandr)
4. Black screen of death on resume from suspend.

This is a Dell Precision 5510 laptop with Nvidia and Intel graphics:

    *-display
            description: 3D controller
            product: GM107GLM [Quadro M1000M]
            vendor: NVIDIA Corporation
            physical id: 0
            bus info: pci@0000:01:00.0
            version: a2
            width: 64 bits
            clock: 33MHz
            capabilities: bus_master cap_list rom
            configuration: driver=nouveau latency=0
            resources: irq:125 memory:dc000000-dcffffff 
  memory:b0000000-bfffffff memory:c0000000-c1ffffff ioport:e000

   *-display
         description: VGA compatible controller
         product: HD Graphics 530
         vendor: Intel Corporation
         physical id: 2
         bus info: pci@0000:00:02.0
         version: 06
         width: 64 bits
         clock: 33MHz
         capabilities: vga_controller bus_master cap_list rom
         configuration: driver=i915 latency=0
         resources: irq:126 memory:db000000-dbffffff  
memory:70000000-7fffffff ioport:f000(size=64) memory:c0000-dffff

I did not realize that the kernel update was at the heart of my trouble, I chased a lot of symptoms that pointed at the use of either gdm3 or lightdm as the display manager, then the Nvidia drivers, then modesetting, but in the end I conclude this particular kernel causes problems that I'm not able to solve. I'm back running the 4.18.10

The first symptom I saw was a failure to start. After the grub phase, I had black screen freeze-up with the message

PKCS#7 signature not signed with a trusted key

The system did not respond to Alt-Ctl-F2 or such, no VT was possible. Comments in this forum pointed the finger at the Nvidia drivers. In retrospect, this may be a gdm3 flaw, rather than Nvidia (Ubuntu 18.04 Boot hangs at PKCS#7 signature not signed with a trusted key, Ubutnu 18.04 - after upgrade - Display/PKCS#7 signature error). I never solved it.

I used the recovery login to clear out the Nvidia drivers and move xorg.conf out of the way. I'd run with the intel drivers.

After that, when gdm3 was the display manager, I came to black screen with just a single "_" showing top left on the screen. One suggestion was that gdm3 was trying to launch a Wayland session. I tried the fix to disable Wayland (gdm3 does not start in ubuntu 18.04), no help. Those posts suggest there is a way to make gdm3 work, but more posts recommend using lightdm instead.

So I changed display manager to lightdm. However, even after that, I had black screen of death after grub and I found advice about putting settings in the grub setup for nomodeset or enforce restrictions on nouveau. After a lot of fiddling around, the system would reach the login window. However, I saw 2 problems after that. The video would not resume after suspend (but I could log in with SSH) and external monitors were not detected (probably because of all the no mode setting steps I'd taken).

Not realizing that the mode settings were probably causing the external monitors to be ignored, I re-installed the nvidia drivers (hoping somehow the PKCS key issue would solve itself). That resulted in a black screen of death at startup, but Alt-Ctl-F2 did allow a VT so I could look at dmesg.

After a lot of restarts, I finally decided to try the older kernel, 4.18.0-10, and after that lightdm would start. Suspend would work. I had to remove all of the nomodesetting things I'd put into grub config (and re-run update-grub) in order to get external monitors to work. Also, in the nvidia file /lib/modprobe.d/nvidia-kms.conf, it had to be put back

# This file was generated by nvidia-prime
# Set value to 0 to disable modesetting
options nvidia-drm modeset=1

and initramfs had to be executed.

I have found many sites and posts about video problems and they may offer helpful advice, but none of them helped me with kernel 4.18.0.11.12. I spent a couple of days chasing those fixes, but wish I had just tested the older kernel first.

My suggestion if that if an update in the kernel occurs, and you start to have black screen or other video problems, be a bit patient with trying to bugshoot those things in the usual way. Run the older kernel to see if it works, and if it does, use it and be happy until the new kernel's problems get worked by the experts.

The only "video fix" that I've learned is--absolutely for sure-- valuable is to remove 2 lines from /etc/environment. I don't know for sure how these lines were inserted in there, but it happened in a previous version of Ubuntu (either by a package like gnome-wobbly-windows or by my manual effort to fix screen tearing in 2017). These last 2 lines in /etc/environment about CLUTTER need to be commented out (or deleted entirely):

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
## CLUTTER_PAINT=disable-clipped-redraws:disable-culling
## CLUTTER_VBLANK=True

If you don't make that change, then video inside Ubuntu Gnome desktop with nvidia drivers is fragmented and choppy. Those 2 lines were, so far as I can tell, inserted by some special-effects packages in older Ubuntu (maybe 17.10) and they were causing lots of trouble for me only with Gnome, but not with XFCE4. Because the problem appeared only in Gnome, I knew it was not an Nvidia problem. (Graphics problem on Ubuntu 18.04 - blurred text + screen flickering)

About troubleshooting with the new kernel: I'm willing to try again, but I want somebody to give advice about whether it is useful to even try and what is the best way to go about it.

In Ubuntu 18.04, my battery life was getting so poor that I ordered a new battery from Dell. I was already doing everything to save battery, running with not-bright screen and the low performance Intel driver (not Nvidia performance video).

After installing 18.10, the battery life is more than doubled. Yesterday I used the system for 4 hours on a wireless network and the battery got down to 13%. Before the upgrade, it was, at best, 2 hours, often shorter.

I am pretty enthusiastic.

However, I have frequent video flickering that I did not see before. I'm using the XFCE4 desktop and the compiz window manager. These were OK/stable before, but now, at least once per 30 minutes, I look down and see flickering as the panel is redrawn. When I plug into a projector, it gets worse. The problem appears like long white "streaks" that jitter.

Articles about power management in Ubuntu say that the designers did not make power-saving changes in the past because of instabilities in access to devices. They mention USB and hard disk, but I wonder if video is related:

https://www.pcmag.com/news/361315/ubuntu-18-10-aims-to-improve-laptop-battery-life

Any SparkleShare users out there? I need your thoughts. SS has worked great for 5 years, but not any more. I started an issue on the Sparkle Share Git hub (https://github.com/hbons/SparkleShare/issues/1877), no answer yet. It appears to me the SS documentation emphasis is on the "fool proof" setup for novices. The detailed docs for Linux veterans are, well, non existant so far as I can see.

Ubuntu 18.10 brought with it a new version of the sparkleshare package (3.28). It was a pretty big version jump, my old setup does not work anymore. The first sign of trouble was that on the first reboot after upgrade, the Sparkle program had forgotten the location of my shares. The Sparkle config panels opened asking if I wanted to configure some shares. Nothing I did there worked. Nothing changed on the server end, but new Sparkle just can't interact with it.

So far, I've tried to manually re-configure shares in the Sparkle gui to use the old projects I've tried to edit the projects.xml to do same. But it is not able to talk to the server.

I've looked into some details. The SS config directory moved from ~/.config/sparkleshare to ~/.config/org.sparkleshare.SparkleShare and the config files changed. In the previous version, the config file was config.xml but in new it is named projects.xml, although to my eye it appears they are the same inside.

I've still got the project repos under ~/Sparkleshare and I can use terminal to go in there and manually run git push and git pull to interact with the server. That makes me think the ssh keys are still OK.

However, Sparkle, no matter what I do, can't talk to the other computer.

When Sparkle fails to interact with other system, it gives a display that shows the path I want to connect to correctly, and it asks if I have given ClientID to the other host system. Frankly, I don't understand what it wants. I already confirmed the git ssh keys are good.

My SparkleShare host/server is an old system and it has been fine since 2013. Back in the day, I went on a big mission to set up gitolite and the antique Gitlab on that system, but since then I've lost details on what I did to make that thing work. There was no "dazzle" involved in that setup, I can assure you of that.

I wonder now if Sparkle Share assumes the 2 systems are on the same version of Sparkle Share.

I speak English, all of my menus and such in Ubuntu are in English. I have a repeated problem during the past few years and I wonder if anybody else sees it too.

The CUPS printer system regularly installs a printer ppd file that has Simplified Chinese as the language. Because of that, programs that want to print do not display menu items correctly, presumably because the menu items are in Chinese.

Years ago, I tracked the problem down to a ppd file that comes in with the printer configurator. Here's the top of the ppd file:

*PPD-Adobe: "4.3"
*% Linux Version
*%
*% This program is free software; you can redistribute it and/or modify it
*% under the terms of the GNU General Public License as published by the Free
*% Software Foundation; either version 2 of the License, or (at your option)
*% any later version.
*%
*% This program is distributed in the hope that it will be useful, but WITHOUT
*% ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
*% FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
*% more details.
*%
*% You should have received a copy of the GNU General Public License along with
*% this program; if not, write to the Free Software Foundation, Inc., 59 Temple
*% Place, Suite 330, Boston, MA  02111-1307  USA

*FormatVersion: "4.3"
*LanguageVersion: Simplified Chinese
*LanguageEncoding: None
*FileVersion: "20002.0000"

*Manufacturer: "KONICA MINOLTA"
*ModelName: "KONICA MINOLTA C451 PS/P"
*ShortNickName: "KONICA MINOLTA C451 PS(P)"
*NickName: "KONICA MINOLTA C451 PS(P)"
*PCFileName: "KOC451SCX.ppd"
*Product: "(C451)"
*PSVersion: "(3015.102) 1"

I've gone through the same experience several times over the past few years. I get the correct ppd file from Konica Minolta, install it with the printer configurator. That puts the "right" file in /etc/cups/ppd, it has the name "KM.ppd" because KM is the name I give to that printer. After an Ubuntu version upgrade, the KM.ppd file I insert gets replaced by the Simplified Chinese one. So I put the right one in place of the one that the printer configurator installs there. All is well, the menus work in apps that want to print.

And then an Ubuntu system update comes along and replaces the ppd file with one that assumes I want Simplified Chinese. The first time this happened, it was difficult to figure out. The second time, I knew I'd fixed it before but could not remember how. Now I'm on the 6th or 7th time and it is on the list of things.

This time I've decided to take away write permission on KM.ppd, we'll see if Ubuntu leaves it alone.

Mostly I wonder why other people aren't complaining about this kind of thing. Maybe it is only a Konica-Minolta driver issue?

This is a very little question. Is my sources.list file out of whack?

I upgraded 17.10 on top of 17.04, on top of 16.10, etc. Today I notice some quirky things in my sources.list file. The deb-src lines seem to all be incorrect:

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://us.archive.ubuntu.com/ubuntu/ artful universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe

Note I'm on artful for deb but deb-src is historic. Furthermore, the repositories differ, one release, otherupdates.

More toward the end:

deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
deb http://us.archive.ubuntu.com/ubuntu/ artful-backports restricted universe multiverse
deb http://us.archive.ubuntu.com/ubuntu/ artful-updates universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ artful-security universe restricted multiverse

I'll manually update those. I'm guessing that a glitch happened in the transition out from xenial and it has the updates for y and z flummoxed.

I'm mostly writing this to warn others that there can be mis-matches due to repeated upgrades and that the source package repository can fall out of sync. So if you run "apt-get source xxx" it may be you pull the old/wrong version of something. It is worth a few minutes to inspect /etc/apt/sources.list and the files in /etc/apt/sources.list.d

I use Ubuntu 17.04. I use ssh with X11 forwarding all the time to display GUI programs running on my server locally on my computer.

Ubuntu 17.10 offers Wayland instead of X11 and I've read through a bunch of posts since 2011 about how this "might" affect X11 forwarded apps. I find many predictions of disaster, and many predictions of network transparency.

Some posts claim that I'll be forced to choose at login between X11 or Wayland. However, I have run X11 servers on both Macintosh and Windows so I don't think this is necessarily an either-or choice. But that's just more guessing. How does this actually work?

Today I've tried two methods to access Google drive storage in Ubuntu 17.04. My Desktop is XFCE4.

The first one, using Gnome Online Accounts, does not work well. I see same performance and permission problems in Thunar and Nautilus (er, Files). I followed instructions here:

http://www.webupd8.org/2016/03/use-gnome-318-google-drive-integration.html

I'm able to see files in Google Drive and rename them, but 1) it does not allow files to be deleted, moved or copied in the file manager, 2) it does not interact with the Terminal well, the file names display a long encrypted looking things, and 3) there are long "hang" times where the file manager and the popup menus it creates are frozen.

The second method I tried, a FUSE based tool named google-drive-ocamlfuse, works fine! Instructions:

http://www.omgubuntu.co.uk/2017/04/mount-google-drive-ocamlfuse-linux

They are right. This is more "performant".

The PPA offers that program, it is no longer necessary to compile it for yourself, and so far for me it JUST WORKS. I am able to mount the folder and succeed in fully interacting with files, including viewing, renaming, moving, and copying. All in all, it was a big victory.

Now I wonder...

Question 1. Is this is secure?

google-drive-ocamlfuse seems to bypass the Google 2 factor authentication. How can that be? When I did the Gnome Drive method, it did follow the 2 factor authentication, sending a text to my phone. Is the computer remembering the authentication from the Gnome session when I use the CLI to mount with ocamlfuse?

Question 2. Possible to auto unmount?

There is a real danger is that I will forget to run fusermount -u on the google drive. If I could make laptop suspend automatically unmount that drive it would be good.

In past experience with sshfs, I notice that if I forget to fusermount -u to disconnect, then the whole OS is very slow after a suspend/resume. The OS keeps trying to re-establish connection to files on the now defunct file system).

One other thing worth mentioning. Cleaning out the Gnome Account stuff is not all that easy. I wish I had understood this part before trying it. Gnome installed a lot of packages and I had to go through some fancy dancing to put my Google info into Gnome Online Account. It is easy enough to remove the packages, but cleaning out the account information is not automatic. I found advice for that here:

How to remove Google virtual mount drive from Ubuntu 16.04?

but I worry I'll never get rid of all the hidden files.

Here are all of the packages that came in during this Gnome adventure, by the way:

$ sudo apt-get install gnome-control-center gnome-online-accounts
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  apg dconf-cli dleyna-server gir1.2-ibus-1.0 gkbd-capplet gnome-bluetooth
  gnome-control-center-data gnome-settings-daemon gnome-user-share ibus
  libcolord-gtk1 libdleyna-connector-dbus-1.0-1 libdleyna-core-1.0-3
  libgeocode-glib0 libgnome-bluetooth13 libgnomekbd-common libgnomekbd8
  libgoa-backend-1.0-1 libgupnp-av-1.0-2 libgupnp-dlna-2.0-3 libgweather-3-6
  libgweather-common libnss-myhostname mousetweaks realmd
  ubuntu-system-service unity-control-center-faces
Suggested packages:
  libcanberra-gtk-module apache2-bin libapache2-mod-dnssd ibus-clutter
  ibus-doc
The following NEW packages will be installed:
  apg dconf-cli dleyna-server gir1.2-ibus-1.0 gkbd-capplet gnome-bluetooth
  gnome-control-center gnome-control-center-data gnome-online-accounts
  gnome-settings-daemon gnome-user-share ibus libcolord-gtk1
  libdleyna-connector-dbus-1.0-1 libdleyna-core-1.0-3 libgeocode-glib0
  libgnome-bluetooth13 libgnomekbd-common libgnomekbd8 libgoa-backend-1.0-1
  libgupnp-av-1.0-2 libgupnp-dlna-2.0-3 libgweather-3-6 libgweather-common
  libnss-myhostname mousetweaks realmd ubuntu-system-service
  unity-control-center-faces
0 upgraded, 29 newly installed, 0 to remove and 24 not upgraded.
Need to get 6,153 kB of archives.
After this operation, 30.2 MB of additional disk space will be used.

Today I have a new suspend/resume problem. On Dell Precision 5510 w/Ubuntu 17.04, all was well. But now, resume is not working. I always get restart.

Yesterday, I had a runaway script and it paralyzed the UI. I made a programming error, it caused this script to consume all system resources. I went to another computer and ssh connected with this "frozen" computer. I tried to shut down the system the old fashioned way:

/sbin/shutdown -h now

However, after 20 minutes of waiting, I gave up and held down the power button. The thing will start, it will suspend also. If I open the lid, it wakes up automatically. That is how I know the machine is actually suspended, it starts itself.

However, the machine restarts, instead of resuming, after a suspend.

My working theory is that the unclean crash damaged a settings file that must be rewritten during suspend. This file is a signal that resume from RAM is OK, rather than a restart.

I don't know for sure there is such a file for suspend/resume, but I've found comments here about hybernate/resume which say that it uses a state file to tell if it can try to restore a session.

I expect this problem will disappear at random after some package updates, but it has made me really curious about how a system checks to see if it should restart.

I want to make some workflow graphics. Is there a convenient tool for that?

I found some Git workflow diagrams in Vincent Driessen's Successful Git branching model and Jussi Judin's blog post in response. I'll paste in just a small chunk of Driessen's drawing here to give you an idea what I'm looking for:

I want to create new lovely "cartoonish" drawings of that sort for a project report. I like that they have somewhat "fuzzy" text boxes, pleasant callout shapes with configurable pointers to dots, and colored dots. I wish the editor would make it convenient to re-align pieces. It would be nice if arrows might "move with the dots" to which they point in an "easy" to adjust way.

Can you tell me how it can be done in Ubuntu? I'm aware of dia, which makes less jazzy illustrations.

Please don't say I need a Microsoft Surface to do this :)

This is not a problem, but I'm just curious.

Why does the alphabetical listing of files differ among programs?

It appears to me as though each program implements its own approach for alphabetical sorting of file names. Maybe these flow from the libraries upon which programs draw. Clearly, they have different customs for the treatment of symbols like "_" or "-". I think it is a little odd that these are not consistent.

Here's an example. I create 2 files, "flop.png" and "flop_drop.png". In a BASH shell, the listing has:

-rw-rw-r--  1 pauljohn pauljohn  3547 Apr  1 21:50 flop_drop.jpg
-rw-rw-r--  1 pauljohn pauljohn  3547 Apr  1 21:50 flop.jpg

However, in Nautilus, that is reversed

But in Geeqie, I see same as in BASH:

While the UNIX find program agrees with Nautilus:

$ find . -name "flo*"
./flop.jpg
./flop_drop.jpg

I've seen various wrinkles like this, I don't entirely understand the pattern. I proliferate variations and the ls output in BASH indicates that it is including the suffixes in alphabetical sorting:

-rw-rw-r-- 1 pauljohn pauljohn 3547 Apr  1 21:50 flop_drop.jpg
-rw-rw-r-- 1 pauljohn pauljohn 3547 Apr  1 21:50 flop.jpg
-rw-rw-r-- 1 pauljohn pauljohn 3547 Apr  1 22:14 flop_nop.jpg
-rw-rw-r-- 1 pauljohn pauljohn 3547 Apr  1 22:15 flop_qrop.jpg

But Nautilus always leaves "flop.jpg" first, no matter what follows the underscore. I see Thunar does the same.

However, I installed an image viewer named "gwenview" for comparison. In there, we get something entirely different. The ordering is

flop_drop.jpg
flop_nop.jpg
flop_qrop.jpg
flop.jpg

Are there different schools of thought on how it ought to be done, or are these just accidental differences?

I'm writing to see if you have tried to compile Emacs lately. I want to compile emacs-25.1 but hit a segmentation fault. If you wonder why I want to compile, or why I'm asking here, read on...

I upgraded to Ubuntu 16.10 today and emacs-24.5 still runs, but the toolbar icons have turned invisible. After a suitable amount of googling, I found this problem has appeared through time, usually either a flaw in gtk+, the desktop theme, or Emacs itself. The most recent posts seem to say that there was a bug in the Emacs code that was since fixed (https://bugs.archlinux.org/task/48862).

I figured I'd try emacs25, see if it is fixed there. Many people suggest using the repo offered here, (deb http://ppa.launchpad.net/adrozdoff/emacs/ubuntu yakkety main), however that one is refused by apt-get for a reason I have not seen before:

W: The repository 'http://ppa.launchpad.net/adrozdoff/emacs/ubuntu yakkety Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.

I don't mind compiling programs, so I'll move forward.

My first idea was to take the source deb packaging from that website but trying to build the package resulted in a segmentation fault.

Supposing that there was something wrong in that packaging, I tried to build from source. I end in the same segmentation fault:

$ wget http://ftp.gnu.org/gnu/emacs/emacs-25.1.tar.gz
$ tar xzvf emacs-25.1.tar.gz
$ cd emacs-25.1
$ ./configure --prefix=/usr/local
$ make

After a few thousand lines, I get same seg fault I saw rebuilding package

Loading emacs-lisp/eldoc...
Loading cus-start...
Loading tooltip...
Loading /home/pauljohn/LinuxDownloads/Ubuntu/sources/emacs/emacs-25.1/lisp/leim/leim-list.el (source)...
Finding pointers to doc strings...
Finding pointers to doc strings...done
Dumping under the name emacs
Makefile:736: recipe for target 'bootstrap-emacs' failed  
make[1]: *** [bootstrap-emacs] Segmentation fault (core dumped)
make[1]: Leaving directory '/home/pauljohn/LinuxDownloads/Ubuntu/sources/emacs/emacs-25.1/src'
Makefile:398: recipe for target 'src' failed
make: *** [src] Error 2

While googling the error message, I don't find a fix. I do find plenty of emacs seg faults over time, of course, but they usually give a more informative message. I think the mention of Makefile:736 is referring to the Makefile in the src directory:

bootstrap-emacs$(EXEEXT): temacs$(EXEEXT)
        $(MAKE) -C ../lisp update-subdirs
ifeq ($(CANNOT_DUMP),yes)
        ln -f temacs$(EXEEXT) $@
else
        $(RUN_TEMACS) --batch --load loadup bootstrap
   ifneq ($(PAXCTL_dumped),)
        $(PAXCTL_dumped) emacs$(EXEEXT)
   endif
        mv -f emacs$(EXEEXT) $@
endif

I have not been in this situation in a long time.

I found pages about past seg faults building Emacs

1 https://bbs.archlinux.org/viewtopic.php?id=197841. In Arch linux there is a "hardening" package that was installed and Emacs was failing because of that. I found I had a package "hardening-includes" from Ubuntu 16.10 and I removed that to see if the result would change. No!

2 https://lists.gnu.org/archive/html/bug-gnu-emacs/2015-04/msg00371.html. There was an errant compiler flag. I don't have that flag.

3 http://emacs.1067599.n8.nabble.com/bug-20190-Building-emacs-24-4-against-GCC-5-0-td352965.html says there was an environment flag that was to blame. I don't have that.

The Emacs bug reporting process (https://debbugs.gnu.org/Emacs.html) is, well, difficult me. I can't figure how to submit a new bug.

I uploaded the whole configure/make output in case that is informative:

http://pj.freefaculty.org/scraps/emacs-build-fail-20161013.txt

In Ubuntu 16.04, I use XFCE4 on a Dell Precision 5510 laptop. How to configure mouse+keyboard settings?

I want to change the Alt+middle mouse button behavior, which currently sends the clicked-on window to the bottom of the stack. I'd like to change this in both an external mouse but especially in the touchpad. I'd like to know how to alter all key+mouse combinations, but if I could only alter that one, I'd be a happy guy.

I have found 3 sets of configurations that affect the window manager, but none allow me to edit the mouse button/key modifier combinations. In the Settings panel, I see

1. Window Manger
2. Keyboard
3. Settings Editor

There's a very nice summary of XFCE settings for keyboard here https://forums.linuxmint.com/viewtopic.php?t=212982 It has pointers to the configurators I mentioned. In the past, I've found ways to fiddle these settings in KDE, Compiz, and Gnome. But the XFCE4 is more difficult.

I'm using libinput as a device & touchpad driver. It seems to me I have a window manager / desktop configuration question, not a libinput problem here, but if you tell me otherwise, I'll believe you.

I often want to have just the top or the bottom of a window on screen. I don't want one program to hog the whole screen. For example, I need to refer to a calculation that is displayed in the bottom of a large window. To refer to that calculation, and then write about that in another window, I want to reposition the calculation so that only the very bottom part of the calculation window is showing. (I don't need to see its titlebar or pull-down menus, or even the first 2/3 of the calculation panel).

At the current time, so far as I know, all of the "desktops" for Linux enforce a restriction that makes it impossible to reposition a window so that it is half-off the screen on the top or the bottom.

In the golden days of window mangers (WindowMaker was awesome!), this was not a problem. There were no enforced "boundaries" protecting panels from being covered, so far as I can remember. The problem began with Gnome and KDE, as I recall. When Compiz came along, it enforced a policy that a window could not be repositioned so that its titlebar was off the screen, but ccsm had an option to allow an eager user to change that (called "constrain-Y" as I recall). When I started using OpenBox and XFWM4 based systems, I missed that ability.

It seemed to me that the authors of panels were protecting the primacy of their product too aggressively. I just don't need to see the Gnome or XFCE4 panels when I'm busy writing something.

Edit: I made a screenshot as I was typing the answer to comment below. See here: