I ran into the same issue when I started... malept had the answer of course.
When a python applet is modified for the new build system it requires an entry added into configure.ac
Basically in the case above you need to add the following to AC_OUTPUT
src/file-browser-launcher/file-browser-launcher.desktop.in
Other than that the other thing that jumps out at me is that if something is assigned to APPLET_MAIN_FILE it needs to be removed from dist_applet_DATA
I ran into the same issue when I started... malept had the answer of course.
When a python applet is modified for the new build system it requires an entry added into configure.ac
Basically in the case above you need to add the following to AC_OUTPUT
src/file- browser- launcher/ file-browser- launcher. desktop. in
Other than that the other thing that jumps out at me is that if something is assigned to APPLET_MAIN_FILE it needs to be removed from dist_applet_DATA