stackprotector's questions

I know how to install a specific version of a package. Now I want to upgrade all packages of my system with:

sudo apt upgrade

But for a specific package, I do not want it to upgrade to the latest version, but to a specific one. E. g., currently installed version is 1. Latest available via apt is 3. I want to upgrade to 2. Is it possible with apt?

I maintain an apt mirror by using apt-mirror. It works fine for the packages of bionic and focal. Now, I want to add the files, that are needed to be able to perform release upgrades using this mirror. In /etc/apt/mirror.list I added main/dist-upgrader-all to all update sources that contain these folders.

My /etc/apt/mirror.list currently looks like this:

############# config ##################
#
set base_path    /mnt/usb/ubuntu_mirror
#
# set mirror_path  $base_path/mirror
# set skel_path    $base_path/skel
# set var_path     $base_path/var
# set cleanscript $var_path/clean.sh
# set defaultarch  <running host architecture>
# set postmirror_script $var_path/postmirror.sh
# set run_postmirror 0
set nthreads     20
set _tilde 0
#
############# end config ##############

deb-amd64 http://archive.ubuntu.com/ubuntu bionic main restricted universe multiverse main/dist-upgrader-all
deb-amd64 http://archive.ubuntu.com/ubuntu bionic-security main restricted universe multiverse
deb-amd64 http://archive.ubuntu.com/ubuntu bionic-updates main restricted universe multiverse main/dist-upgrader-all
deb-amd64 http://archive.ubuntu.com/ubuntu bionic-backports main restricted universe multiverse

deb-amd64 http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse main/dist-upgrader-all
deb-amd64 http://archive.ubuntu.com/ubuntu focal-security main restricted universe multiverse
deb-amd64 http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse main/dist-upgrader-all
deb-amd64 http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse

clean http://archive.ubuntu.com/ubuntu

After the addition of main/dist-upgrader-all, the execution of apt-mirror throws the following errors, when processing indexes:

Downloading 352 index files using 20 threads...
Begin time: Wed Aug  2 12:15:38 2021
[20]... [19]... [18]... [17]... [16]... [15]... [14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]... 
End time: Wed Aug  2 12:16:01 2021

Processing translation indexes: [TTTTTTTT]

Downloading 1137 translation files using 20 threads...
Begin time: Wed Aug  2 12:16:03 2021
[20]... [19]... [18]... [17]... [16]... [15]... [14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]... 
End time: Wed Aug  2 12:16:26 2021

Processing DEP-11 indexes: [DDDDDDDD]

Downloading 160 dep11 files using 20 threads...
Begin time: Wed Aug  2 12:16:29 2021
[20]... [19]... [18]... [17]... [16]... [15]... [14]... [13]... [12]... [11]... [10]... [9]... [8]... [7]... [6]... [5]... [4]... [3]... [2]... [1]... [0]... 
End time: Wed Aug  2 12:16:35 2021

Processing indexes: [Papt-mirror: can't open index archive.ubuntu.com/ubuntu//dists/bionic/main/dist-upgrader-all/binary-amd64/Packages in process_index at /usr/bin/apt-mirror line 800.
PPapt-mirror: can't open index archive.ubuntu.com/ubuntu//dists/bionic-updates/main/dist-upgrader-all/binary-amd64/Packages in process_index at /usr/bin/apt-mirror line 800.
PPapt-mirror: can't open index archive.ubuntu.com/ubuntu//dists/focal/main/dist-upgrader-all/binary-amd64/Packages in process_index at /usr/bin/apt-mirror line 800.
PPapt-mirror: can't open index archive.ubuntu.com/ubuntu//dists/focal-updates/main/dist-upgrader-all/binary-amd64/Packages in process_index at /usr/bin/apt-mirror line 800.
P]

So, what am I doing wrong? How can I successfully add the files from main/dist-upgrader-all to my mirror, so that clients using this mirror can perform release upgrades?

It seems to be a lot of trouble to get MySQL running with lower_case_table_names=1 as can be seen in:

• lower_case_table_names=1 on Ubuntu 18.04 doesn't let mysql to start
• lower_case_table_names Settings in MySQL 8.0.12
• Set up mysql 8 with lower_case_table_names on CentOS 7
• Mysql : can't set lower_case_table_names variable
• lower_case_table_names option not working

I'm trying to install MySQL 8.0.19 on Ubuntu Server 20.04 LTS. lower_case_table_names=1 cannot be set after mysql has already been initialized, which happens automatically when installing from the package repositories.

According to the documentation Server System Variables | sysvar_lower_case_table_names:

For APT installations on Debian and Ubuntu, however, the server is initialized for you, and there is no opportunity to configure the setting in an option file beforehand. You must therefore use the debconf-set-selection utility prior to installing MySQL using APT to enable lower_case_table_names. To do so, run this command before installing MySQL using APT:

sudo debconf-set-selections <<< "mysql-server mysql-server/lowercase-table-names select Enabled"

I did that on a freshly installed Ubuntu Server 20.04 and ran sudo apt-get install mysql-server afterwards, but it did not change lower_case_table_names to 1.

If at all, what am I doing wrong? How can I successfully install MySQL 8.0 with lower_case_table_names set to 1?