I trust you with the 24.94 GB, but could you post a picture of your phones storage? (Settings -> Storage Settings). Is it a “clean” install? Have you wiped your phone before? Have you “played around” with options like disk encryption or fast boot before?
Without knowing more, I would try a hard reset and reinstall. But maybe others here have better ideas so better wait a bit
Thanks for posting all the information. Yes, I think a read-only fs could maybe trigger a similar error message. Maybe @Spielmops has a point. I’m not sure what kind of error code is returned/used. I thought the error codes for disc full and read only differ, but it’s been a while and maybe there is some kind of layer around all this.
If you install apks how do you do this? Using adb? The recovery? Clicking on them with a filemanager? Have you enabled root access?
If you use adb like adb install my-app.apk what kind of error message do you get?
I have succeeded to recompile and use Fairphone Open OS. I used Ubuntu precise distribution. My build environment is a NayuOS laptop with chroot made by crouton.
I had to retry a few times. It seems that the code download process and build process is not idempotent. This means that stopping build in the middle can not be recovered sometimes. I guess there is nothing much to do about this. Even git has this problem in some rare cases.
I use now F-Droid and APKPure appstores. I got some nice Free Software (920 Text Edtitor, Flym, K-9, Termux, OsmAnd). I could run Waze, Line, Wechat, FB Messenger.
Some apps do not work though (ex. Autolib) because of lack of google play services and location support, even though I tried all NLP plugins. But that is OK for me.
One note: I deactivated the default Email and Internet browser. This makes my system more reliable because the default Email client was always crashing.