bwrap: execvp application: No such file or directory (GNOME Builder Flatpak)

When I try to run the GJS GNOME Example application from GNOME Builder 3.32.4 (Flatpak'ed), I get the error:

bwrap: execvp <application-id>: No such file or directory

I tried "Clean" and "Rebuild" the project, but with no help.

This only happens for the example GJS GNOME application. The C GNOME Application seems to run fine.

Solution

Found the answer myself. GNOME Builder's build directory .var/app/org.gnome.Builder/cache/gnome-builder/projects/<app-name>/builds/ turned out to be empty. I have no idea how it happened, but I solved it by restarting GNOME Builder.