I already noticed that somehow, apt-get does not seem to work on the Endless system (although, strangely, it is actually installed, but there are error messages which, even when in recovery mode, cannot be eliminated, such as
"not using locking for read only lock file … and chmod won’t change it in recovery mode). The alternative is suggested to be flatpak. But: How exactly do I install things with flatpak (I have read the documentation, but I must admit, as a newbie to Linux, that I could not understand exactly since some things have to be specified which I do not know), especially from github? And how do I get “make” commands and the like, e.g. from g++ etc. (without installing a heavy package like Android or stuff like this)?
Thanks in advance