testgtk fails to find gcc in home directory

[TamaMcGlinn]

The actual gtk installation seems to work, but the subsequent test of the install fails.

To install, I did ./configure --with-GL=no and then sudo make all install.

That fails with:

/opt/GNAT/2020/bin/../libexec/gcc/x86_64-pc-linux-gnu/9.3.1/ld: /home/tama/code/ada/adacore/gtkada/src/lib/gtkada/static/libgtkada.a(glib-spawn.
o): in function `glib__spawn__spawn_command_line_async':
glib-spawn.adb:(.text+0x165): undefined reference to `gnat_spawn_command_line_async'
collect2: error: ld returned 1 exit status
/opt/GNAT/2020/bin/../libexec/gcc/x86_64-pc-linux-gnu/9.3.1/ld: /home/tama/code/ada/adacore/gtkada/src/lib/gtkada/static/libgtkada.a(glib-spawn.
o): in function `glib__spawn__spawn_command_line_async':
glib-spawn.adb:(.text+0x165): undefined reference to `gnat_spawn_command_line_async'
collect2: error: ld returned 1 exit status
   link of test_rtree.adb failed
   failed command was: /opt/GNAT/2020/bin/gcc test_rtree.o b__test_rtree.o /home/tama/code/ada/adacore/gtkada/src/lib/gtkada_gl/static/libgtkada
_gl.a /home/tama/code/ada/adacore/gtkada/src/lib/gtkada/static/libgtkada.a -L/home/tama/code/ada/adacore/gtkada//lib -L/home/tama/code/ada/adaco
re/gtkada//bin -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -Wl,--exp
ort-dynamic -lgmodule-2.0 -pthread -lglib-2.0 -lfontconfig -lfreetype -L/home/tama/code/ada/adacore/gtkada/testgtk/obj/ -L/home/tama/code/ada/ad
acore/gtkada/testgtk/obj/ -L/home/tama/code/ada/adacore/gtkada/src/lib/gtkada/static/ -L/home/tama/code/ada/adacore/gtkada/src/lib/gtkada_gl/sta
tic/ -L/home/tama/code/ada/adacore/gtkada/testgtk/task_project/obj/ -L/opt/GNAT/2020/lib/gcc/x86_64-pc-linux-gnu/9.3.1/adalib/ -shared-libgcc /o
pt/GNAT/2020/lib/gcc/x86_64-pc-linux-gnu/9.3.1/adalib/libgnarl.a /opt/GNAT/2020/lib/gcc/x86_64-pc-linux-gnu/9.3.1/adalib/libgnat.a -lrt -lpthrea
d -ldl -Wl,-rpath-link,/opt/GNAT/2020/lib/gcc/x86_64-pc-linux-gnu/9.3.1//adalib -Wl,-z,origin,-rpath,$ORIGIN/..//lib:$ORIGIN/..//bin:$ORIGIN//ob
j:$ORIGIN/..//src/lib/gtkada/static:$ORIGIN/..//src/lib/gtkada_gl/static:$ORIGIN//task_project/obj:/opt/GNAT/2020/lib/gcc/x86_64-pc-linux-gnu/9.
3.1/adalib -o /home/tama/code/ada/adacore/gtkada/testgtk//test_rtree

Noting the double forward slashes in the failed command, I suspect there is an environment variable that needs to be set to tell the Makefile where my GNAT installation is. gnat_spawn_command_line_async is defined in my installation of /opt/GNAT/2020/lib/gnatstudio/libgtkada.so.21.0w as found by doing a find | xargs grep in the GNAT install directory and seeing that that binary file matches.

I also went into testgtk and did: gprbuild -j0 -m -p -XLIBRARY_TYPE=static -Ptestgtk.gpr -aP ../src but it fails with a different error, which is odd:

gprbuild: raised CONSTRAINT_ERROR : unable to locate "/home/tama/code/gcc"
[/opt/GNAT/2020/bin/gprbuild]
0x736c19
0x4f6e01
0x4f88cc
0x4f991e
0x4f9da7
0x4f9e25
0x4b4636
0x4a4474
[/lib/x86_64-linux-gnu/libc.so.6]
0x7f88d5524099
[/opt/GNAT/2020/bin/gprbuild]
0x4a44c7

I have no idea why it would look for a ~/gcc which I don't have. Perhaps this project will only work if located inside /opt/GNAT/2020/somewhere ? Where do you normally place this repository over at AdaCore?