(Adding back Jörg and Calum to recipients as more contributors to test/debug/fix the Buster -> Bullseye upgrade issues would be welcome)
As Faustin pointed out, Bullseye has both galera-3 and galera-4. This is so the distro is compatible with running whatever version of MariaDB you want. Galera-3 will be in Debian (and Ubuntu) repositories for as long as somebody is still using MariaDB 10.1-10.3. MariaDB 10.3 in Debian Buster depends on Galera 3. Thus, if you install Galera 4, which uninstalls Galera 3 (they cannot be installed at the same time on the same system as the files and commands overlap), and as a dependency of MariaDB 10.3 goes away it also uninstalls. Here is the debug output: # Starting point Debian Buster container with mariadb-server installed # dpkg -l | grep -e mariadb -e mysql -e galera ii galera-3 25.3.25-2 amd64 Replication framework for transactional applications ii libdbd-mysql-perl:amd64 4.050-2 amd64 Perl5 database interface to the MariaDB/MySQL database ii libmariadb3:amd64 1:10.3.27-0+deb10u1 amd64 MariaDB database client library ii mariadb-client-10.3 1:10.3.27-0+deb10u1 amd64 MariaDB database client binaries ii mariadb-client-core-10.3 1:10.3.27-0+deb10u1 amd64 MariaDB database core client binaries ii mariadb-common 1:10.3.27-0+deb10u1 all MariaDB common metapackage ii mariadb-server 1:10.3.27-0+deb10u1 all MariaDB database server (metapackage depending on the latest version) ii mariadb-server-10.3 1:10.3.27-0+deb10u1 amd64 MariaDB database server binaries ii mariadb-server-core-10.3 1:10.3.27-0+deb10u1 amd64 MariaDB database core server files ii mysql-common 5.8+1.0.5 all MySQL database common files, e.g. /etc/mysql/my.cnf # Buster repo enabled, apt update ran and ready to upgrade # If the apt debug output is too verbose, you don't need to use all of the three provided debug flags at the same time. # apt-get install galera-4 -o Debug::pkgProblemResolver=1 Reading package lists... Done Building dependency tree Reading state information... Done Starting pkgProblemResolver with broken count: 1 Starting 2 pkgProblemResolver with broken count: 1 Investigating (0) mariadb-server-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Broken mariadb-server-10.3:amd64 Depends on galera-3:amd64 < 25.3.25-2 | 25.3.31-2+b1 @ii umR > (>= 25.3) Considering galera-3:amd64 -1 as a solution to mariadb-server-10.3:amd64 -1 Removing mariadb-server-10.3:amd64 rather than change galera-3:amd64 Investigating (1) mariadb-server:amd64 < 1:10.3.27-0+deb10u1 | 1:10.5.9-1 @ii umH Ib > Broken mariadb-server:amd64 Depends on mariadb-server-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mR > (>= 1:10.3.27-0+deb10u1) Considering mariadb-server-10.3:amd64 -1 as a solution to mariadb-server:amd64 -1 Re-Instated mariadb-common:amd64 Re-Instated libmd0:amd64 Re-Instated libbsd0:amd64 Re-Instated libedit2:amd64 Re-Instated mariadb-client-core-10.5:amd64 Re-Instated mariadb-client-10.5:amd64 Re-Instated libcrypt1:amd64 Re-Instated libc6:amd64 Re-Instated libpcre2-8-0:amd64 Re-Instated libsnappy1v5:amd64 Re-Instated mariadb-server-core-10.5:amd64 Re-Instated libprocps8:amd64 Re-Instated procps:amd64 Re-Instated mariadb-server-10.5:amd64 Re-Instated mariadb-server:amd64 Investigating (1) mariadb-client-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Broken mariadb-client-10.3:amd64 Conflicts on virtual-mysql-client:amd64 < none @un H > Considering mariadb-client-10.5:amd64 0 as a solution to mariadb-client-10.3:amd64 -1 Removing mariadb-client-10.3:amd64 rather than change virtual-mysql-client:amd64 Investigating (2) libc-bin:amd64 < 2.28-10 | 2.31-11 @ii umH NPb Ib > Broken libc-bin:amd64 Depends on libc6:amd64 < 2.28-10 -> 2.31-11 @ii umU IPb > (< 2.29) Considering libc6:amd64 2831 as a solution to libc-bin:amd64 5099 Added libc6:amd64 to the remove list Fixing libc-bin:amd64 via keep of libc6:amd64 Investigating (2) mariadb-client-core-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-client-core-10.5:amd64 Conflicts on virtual-mysql-client-core:amd64 < none @un H > Considering mariadb-client-core-10.3:amd64 -1 as a solution to mariadb-client-core-10.5:amd64 0 Added mariadb-client-core-10.3:amd64 to the remove list Broken mariadb-client-core-10.5:amd64 Breaks on mariadb-client-core-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Considering mariadb-client-core-10.3:amd64 -1 as a solution to mariadb-client-core-10.5:amd64 0 Added mariadb-client-core-10.3:amd64 to the remove list Fixing mariadb-client-core-10.5:amd64 via remove of mariadb-client-core-10.3:amd64 Fixing mariadb-client-core-10.5:amd64 via remove of mariadb-client-core-10.3:amd64 Investigating (2) mariadb-server-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-server-10.5:amd64 Depends on libc6:amd64 < 2.28-10 | 2.31-11 @ii umH > (>= 2.29) Considering libc6:amd64 5099 as a solution to mariadb-server-10.5:amd64 0 Holding Back mariadb-server-10.5:amd64 rather than change libc6:amd64 Investigating (2) mariadb-server-core-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-server-core-10.5:amd64 Depends on libc6:amd64 < 2.28-10 | 2.31-11 @ii umH > (>= 2.30) Considering libc6:amd64 5099 as a solution to mariadb-server-core-10.5:amd64 0 Holding Back mariadb-server-core-10.5:amd64 rather than change libc6:amd64 Investigating (2) mariadb-server:amd64 < 1:10.3.27-0+deb10u1 -> 1:10.5.9-1 @ii umU Ib > Broken mariadb-server:amd64 Depends on mariadb-server-10.5:amd64 < none | 1:10.5.9-1 @un uH > (>= 1:10.5.9-1) Considering mariadb-server-10.5:amd64 0 as a solution to mariadb-server:amd64 -1 Removing mariadb-server:amd64 rather than change mariadb-server-10.5:amd64 Done The following packages were automatically installed and are no longer required: libaio1 libcgi-fast-perl libcgi-pm-perl libconfig-inifiles-perl libdbd-mysql-perl libdbi-perl libencode-locale-perl libfcgi-perl libgdbm-compat4 libgdbm6 libhtml-parser-perl libhtml-tagset-perl libhtml-template-perl libhttp-date-perl libhttp-message-perl libio-html-perl liblwp-mediatypes-perl libmariadb3 libncurses6 libperl5.28 libpopt0 libreadline5 libsnappy1v5 libterm-readkey-perl libtimedate-perl liburi-perl libwrap0 lsof mariadb-common mariadb-server-core-10.3 mysql-common netbase perl perl-modules-5.28 psmisc rsync socat Use 'apt autoremove' to remove them. The following additional packages will be installed: gcc-10-base libcrypt1 libgcc-s1 libsnappy1v5 libstdc++6 mariadb-common The following packages will be REMOVED: galera-3 mariadb-client-10.3 mariadb-client-core-10.3 mariadb-server mariadb-server-10.3 The following NEW packages will be installed: galera-4 gcc-10-base libcrypt1 libgcc-s1 The following packages will be upgraded: libsnappy1v5 libstdc++6 mariadb-common The key debug output above is > Broken mariadb-server-10.3:amd64 Depends on galera-3:amd64 < 25.3.25-2 | > 25.3.31-2+b1 @ii umR > (>= 25.3) If I simply run "apt-get upgrade" it will not remove any packages. If I run "apt-get dist-upgrade" it will remove old MariaDB: > The following packages will be REMOVED: > mariadb-client-10.3 mariadb-client-core-10.3 mariadb-server > mariadb-server-10.3 mariadb-server-core-10.3 Study the debug output below: # apt-get dist-upgrade -o Debug::pkgProblemResolver=1 Reading package lists... Done Building dependency tree Reading state information... Done Starting pkgProblemResolver with broken count: 10 Starting 2 pkgProblemResolver with broken count: 10 Investigating (0) mariadb-client-core-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-client-core-10.5:amd64 Conflicts on virtual-mysql-client-core:amd64 < none @un H > Considering mariadb-client-core-10.3:amd64 -3 as a solution to mariadb-client-core-10.5:amd64 0 Added mariadb-client-core-10.3:amd64 to the remove list Broken mariadb-client-core-10.5:amd64 Breaks on mariadb-client-core-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Considering mariadb-client-core-10.3:amd64 -3 as a solution to mariadb-client-core-10.5:amd64 0 Added mariadb-client-core-10.3:amd64 to the remove list Fixing mariadb-client-core-10.5:amd64 via remove of mariadb-client-core-10.3:amd64 Fixing mariadb-client-core-10.5:amd64 via remove of mariadb-client-core-10.3:amd64 Investigating (0) mariadb-client-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-client-10.5:amd64 Conflicts on virtual-mysql-client:amd64 < none @un H > Considering mariadb-client-10.3:amd64 -2 as a solution to mariadb-client-10.5:amd64 0 Added mariadb-client-10.3:amd64 to the remove list Broken mariadb-client-10.5:amd64 Breaks on mariadb-client-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Considering mariadb-client-10.3:amd64 -2 as a solution to mariadb-client-10.5:amd64 0 Added mariadb-client-10.3:amd64 to the remove list Fixing mariadb-client-10.5:amd64 via remove of mariadb-client-10.3:amd64 Fixing mariadb-client-10.5:amd64 via remove of mariadb-client-10.3:amd64 Investigating (0) galera-4:amd64 < none -> 26.4.7-3 @un uN Ib > Broken galera-4:amd64 Conflicts on galera-3:amd64 < 25.3.25-2 -> 25.3.31-2+b1 @ii umU Ib > Considering galera-3:amd64 0 as a solution to galera-4:amd64 0 Holding Back galera-4:amd64 rather than change galera-3:amd64 Investigating (0) mariadb-server-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-server-10.5:amd64 Depends on galera-4:amd64 < none | 26.4.7-3 @un uH > (>= 26.4) Considering galera-4:amd64 0 as a solution to mariadb-server-10.5:amd64 0 Holding Back mariadb-server-10.5:amd64 rather than change galera-4:amd64 Investigating (0) mariadb-server-core-10.5:amd64 < none -> 1:10.5.9-1 @un uN Ib > Broken mariadb-server-core-10.5:amd64 Conflicts on virtual-mysql-server-core:amd64 < none @un H > Considering mariadb-server-core-10.3:amd64 -2 as a solution to mariadb-server-core-10.5:amd64 0 Added mariadb-server-core-10.3:amd64 to the remove list Broken mariadb-server-core-10.5:amd64 Breaks on mariadb-server-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Considering mariadb-server-10.3:amd64 -4 as a solution to mariadb-server-core-10.5:amd64 0 Added mariadb-server-10.3:amd64 to the remove list Broken mariadb-server-core-10.5:amd64 Breaks on mariadb-server-core-10.3:amd64 < 1:10.3.27-0+deb10u1 @ii mK Ib > Considering mariadb-server-core-10.3:amd64 -2 as a solution to mariadb-server-core-10.5:amd64 0 Added mariadb-server-core-10.3:amd64 to the remove list Fixing mariadb-server-core-10.5:amd64 via remove of mariadb-server-core-10.3:amd64 Fixing mariadb-server-core-10.5:amd64 via remove of mariadb-server-10.3:amd64 Fixing mariadb-server-core-10.5:amd64 via remove of mariadb-server-core-10.3:amd64 Investigating (1) mariadb-server:amd64 < 1:10.3.27-0+deb10u1 -> 1:10.5.9-1 @ii umU Ib > Broken mariadb-server:amd64 Depends on mariadb-server-10.5:amd64 < none | 1:10.5.9-1 @un uH > (>= 1:10.5.9-1) Considering mariadb-server-10.5:amd64 0 as a solution to mariadb-server:amd64 0 Removing mariadb-server:amd64 rather than change mariadb-server-10.5:amd64 Done Calculating upgrade... Done The following packages were automatically installed and are no longer required: galera-3 gcc-8-base libaio1 libapt-pkg5.0 libcgi-fast-perl libcgi-pm-perl libclone-perl libconfig-inifiles-perl libdbd-mysql-perl libdbi-perl libencode-locale-perl libfcgi-bin libfcgi-perl libfcgi0ldbl libffi6 libgcc1 libgdbm-compat4 libgdbm6 libhogweed4 libhtml-parser-perl libhtml-tagset-perl libhtml-template-perl libhttp-date-perl libhttp-message-perl libio-html-perl liblwp-mediatypes-perl libmariadb3 libncurses6 libnettle6 libperl5.28 libperl5.32 libpopt0 libreadline5 libreadline7 libsnappy1v5 libterm-readkey-perl libtimedate-perl liburi-perl libwrap0 lsof mariadb-common mysql-common netbase perl perl-modules-5.28 perl-modules-5.32 psmisc rsync socat Use 'apt autoremove' to remove them. The following packages will be REMOVED: mariadb-client-10.3 mariadb-client-core-10.3 mariadb-server mariadb-server-10.3 mariadb-server-core-10.3 The following NEW packages will be installed: bsdextrautils gcc-10-base krb5-locales libapt-pkg6.0 libbpf0 libbsd0 libclone-perl libcrypt1 libfcgi-bin libfcgi0ldbl libffi7 libgcc-s1 libgssapi-krb5-2 libhogweed6 libk5crypto3 libkeyutils1 libkrb5-3 libkrb5support0 libmd0 libnettle8 libnsl2 libnss-nis libnss-nisplus libpcre2-8-0 libperl5.32 libreadline8 libtirpc-common libtirpc3 libxxhash0 logsave perl-modules-5.32 The following packages will be upgraded: apt base-files base-passwd bash bsdutils coreutils dash debconf debian-archive-keyring debianutils diffutils dpkg e2fsprogs fdisk findutils galera-3 gawk gpgv grep gzip hostname init-system-helpers iproute2 iputils-ping libacl1 libaio1 libattr1 libaudit-common libaudit1 libblkid1 libbz2-1.0 libc-bin libc6 libcap-ng0 libcap2 libcap2-bin libcgi-fast-perl libcgi-pm-perl libcom-err2 libconfig-inifiles-perl libdb5.3 libdbd-mysql-perl libdbi-perl libdebconfclient0 libelf1 libencode-locale-perl libext2fs2 libfcgi-perl libfdisk1 libgcrypt20 libgdbm-compat4 libgdbm6 libgmp10 libgnutls30 libgpg-error0 libgpm2 libhtml-parser-perl libhtml-tagset-perl libhtml-template-perl libhttp-date-perl libhttp-message-perl libidn2-0 libio-html-perl liblwp-mediatypes-perl liblz4-1 liblzma5 libmariadb3 libmnl0 libmount1 libmpfr6 libncurses6 libncursesw6 libp11-kit0 libpam-modules libpam-modules-bin libpam-runtime libpam0g libpcre3 libpopt0 libseccomp2 libselinux1 libsemanage-common libsemanage1 libsepol1 libsigsegv2 libsmartcols1 libsnappy1v5 libss2 libssl1.1 libstdc++6 libsystemd0 libtasn1-6 libterm-readkey-perl libtimedate-perl libtinfo6 libudev1 libunistring2 liburi-perl libuuid1 libwrap0 libxtables12 libzstd1 login lsb-base lsof mariadb-common mawk mount mysql-common ncurses-base ncurses-bin netbase passwd perl perl-base psmisc readline-common rsync socat sysvinit-utils tar tzdata util-linux zlib1g What can you read from above? Next, to have a cycle of charging and testing, you can use a local Packages file and run upgrade testing against it: # ensure there are no other repos in use rm /etc/apt/sources.lis # get latest Packages locally as a file curl -O http://ftp.debian.org/debian/dists/sid/main/binary-amd64/Packages.xz unxz Packages.xz cp Packages Packages.orig # test whatever changes you want nano Packages diff -u Packages.orig Packages --- Packages.orig 2021-05-13 14:35:57.417682274 -0700 +++ Packages 2021-05-13 14:36:10.370366409 -0700 @@ -211849,11 +211849,7 @@ Installed-Size: 2381 Maintainer: Debian MySQL Maintainers <pkg-mysql-ma...@lists.alioth.debian.org> Architecture: amd64 -Replaces: galera -Provides: galera, galera4, percona-xtradb-cluster-galera-26, wsrep Depends: libc6 (>= 2.17), libgcc-s1 (>= 3.0), libssl1.1 (>= 1.1.0), libstdc++6 (>= 9) -Conflicts: galera-3, garbd-2, garbd-3, garbd2, garbd3, percona-galera-3, percona-galera-4, percona-xtradb-cluster-galera, percona-xtradb-cluster-galera-2.x, percona-xtradb-cluster-galera-3.x, percona-xtradb-cluster-galera-4.x, percona-xtradb-cluster-garbd-2.x, percona-xtradb-cluster-garbd-3.x -Breaks: galera Description: Replication framework for transactional applications Homepage: https://www.galeracluster.com/ Description-md5: fe238c5e6ce783e128515e8bc966eacf apt-get -o Debug::pkgProblemResolver=1 --with-source ./Packages install galera-4 Reading package lists... Done Building dependency tree Reading state information... Done Starting pkgProblemResolver with broken count: 0 Starting 2 pkgProblemResolver with broken count: 0 Done The following packages were automatically installed and are no longer required: libffi6 libhogweed4 Use 'apt autoremove' to remove them. The following additional packages will be installed: libstdc++6 The following NEW packages will be installed: galera-4 The following packages will be upgraded: libstdc++6 1 upgraded, 1 newly installed, 0 to remove and 122 not upgraded. With these detailed tips you should be able to help out with debugging. I hope you can help me immediately today/this weekend so we can upload MariaDB 10.5.10 on Monday to Debian Sid (and then Bullseye).