(Migrated from Ubuntu forums.)
I'm somewhat new at building, so I'm hoping this is an easy explanation.
Downloaded Nautilus source to patch for transparent background.
Patching went well and fine.
During building I received this:
Making all in libnautilus-private
make[2]: Entering directory `/home/[x]/nautilus-2.32.0/libnautilus-private'
GEN nautilus-marshal.h
GEN nautilus-marshal-guts.c
CC nautilus-autorun.lo
gcc: @APP_INDICATOR_CFLAGS@: No such file or directory
make[2]: *** [nautilus-autorun.lo] Error 1
make[2]: Leaving directory `/home/[x]/nautilus-2.32.0/libnautilus-private'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/[x]/nautilus-2.32.0'
make: *** [all] Error 2