Actually, I just noticed I couldn't run "cat" as regular user but I could as root how could that form a "multiversing" be -technically- happening (other than having forces actively messing with your work)?
export _GRAALVM_HOME=.../graalvm-ce-java17-22.1.0 export PATH=${PATH}:${_GRAALVM_HOME}/bin which javac which java $ bash: which: command not found # apt-get install which Reading package lists... Done Building dependency tree... Done Reading state information... Done E: Unable to locate package which # # cat /etc/apt/sources.list # deb cdrom:[Official Debian GNU/Linux Live 11.2.0 lxde 2021-12-18T12:41]/ bullseye main #deb cdrom:[Official Debian GNU/Linux Live 11.2.0 lxde 2021-12-18T12:41]/ bullseye main deb http://security.debian.org/debian-security bullseye-security main deb-src http://security.debian.org/debian-security bullseye-security main # bullseye-updates, to get updates before a point release is made; # see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports # A network mirror was not selected during install. The following entries # are provided as examples, but you should amend them as appropriate # for your mirror of choice. # deb http://deb.debian.org/debian/ bullseye-updates main deb-src http://deb.debian.org/debian/ bullseye-updates main deb http://deb.debian.org/debian bullseye main contrib non-free deb-src http://deb.debian.org/debian bullseye main contrib non-free deb http://deb.debian.org/debian-security/ bullseye-security main contrib non-free deb-src http://deb.debian.org/debian-security/ bullseye-security main contrib non-free deb http://deb.debian.org/debian bullseye-updates main contrib non-free deb-src http://deb.debian.org/debian bullseye-updates main contrib non-free #This system was installed using small removable media # (e.g. netinst, live or single CD). The matching "deb cdrom" # entries were disabled at the end of the installation process. # For information about how to configure apt package sources, # see the sources.list(5) manual. # which bash /usr/bin/bash #