After upgrading my system from Ubuntu 18.04 to 20.04, I had some graphical glitches and had to reinstall xorg (following this answer). Everything seemed to work fine, except that I could not launch Steam anymore. I tried reinstalling Steam, including removing all the Steam related folders in /home, but to no avail. First time booting Steam after reinstall, a window with a progress bar pops up stating that "Pins potentially out of date ... rebuilding" and then nothing. All other times, there is no graphical feedback whatsoever.
The terminal output at first glance does not seem to point towards any missing packages or anything either, so I am out of ideas. Most of the related reports I find online turn out to be related to proprietary graphics drivers of dedicated GPU's (typically NVidia), but I only have an integrated Intel chipset and want to play some indie games
Running Steam on ubuntu 20.04 64-bit STEAM_RUNTIME is enabled automatically Pins up-to-date! Can't find 'steam-runtime-check-requirements', continuing anyway /home/nicolas/.local/share/Steam/ubuntu12_32/steam [2020-11-07 13:26:07] Startup - updater built Jul 28 2020 22:37:33 ILocalize::AddFile() failed to load file "public/steambootstrapper_english.txt". Installing breakpad exception handler for appid(steam)/version(0) free(): invalid pointer No minidump written, nothing to upload. /home/nicolas/.local/share/Steam/steam.sh: regel 750: 19858 Afgebroken (geheugendump gemaakt) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"