Running a debug session for any c project compiled with flatpak the only breakpoint that works is the initial one (stop on main function). Using host it works correctly

Does this reproduce for you?

It doesn't make a difference, but as I will post code references I show here the source code used

https://github.com/albfan/gtask-example/

Seing log for debug session, main function is located in a main.c file which path is like:

Temporary breakpoint 1, main (argc=1, argv=0x7ffd97005c08) at ../../../../../../../../../Projects/gtask-example/src/main.c:61

Asking for relative and full path for source files to gdb:

-file-list-exec-source-files

you get a long list (shortened here to interesting file):

files=[
{file="../../../../../../../../../Projects/gtask-example/src/main.c"
,fullname="/home/alberto/.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589ae573-local-flatpak-org.gnome.Platform-x86_64-master/../../../../../../../../../Projects/gtask-example/src/main.c"}
...

It seems that gdb operates from a reference to builddir:

/home/alberto/.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589a    e573-local-flatpak-org.gnome.Platform-x86_64-master

I do ask gdb about its current working directory:

-environment-pwd

And says it is 

/home/alberto

Looking at path Builder pass to gdb

/home/alberto/Projects/gtask-example/src/main.c

it should be the same path (as applying ../ all the builddir dirs disappears)

But for whatever reason it doesn't.

This patch makes it work: translating replacing /home/alberto/ into buildir + (several ../)

I really don't know how to do this cleanly, so this is only a WIP.

To convert Builder file

/home/alberto/Projects/gtask-example/src/main.c

into gdb known file path:

/home/alberto/.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589ae573-local-flatpak-org.gnome.Platform-x86_64-master/../../../../../../../../../Projects/gtask-example/src/main.c

I guess we should:

1. Remove cwd from builddir

.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589ae573-local-flatpak-org.gnome.Platform-x86_64-master/

2 turn all that paths into ..

../../../../../../../../../

3. concat that with builddir

/home/alberto/.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589ae573-local-flatpak-org.gnome.Platform-x86_64-master/ + ../../../../../../../../../

4. Remove cwd from Builder path

Projects/gtask-example/src/main.c

5. concat

/home/alberto/.var/app/org.gnome.Builder/cache/gnome-builder/projects/gtask-example/builds/org.gnome.Gtask-Example.json-0601fcfb2fbf01231dd228e0b218301c589ae573-local-flatpak-org.gnome.Platform-x86_64-master/../../../../../../../../../ + Projects/gtask-example/src/main.c

I think I can implement that if the algorithm is correct, but maybe there's something better that will fix this