Bug#689366: allegro5: FTBFS on the Hurd: 'PATH_MAX' undeclared

[Aaron M. Ucko]

Source: allegro5
Version: 2:5.0.7-2
Severity: important
Justification: fails to build from source

The hurd-i386 build of allegro5 failed because the Hurd has no
hardcoded PATH_MAX:

[  3%] Building C object CMakeFiles/allegro.dir/src/file_stdio.c.o
/usr/bin/gcc  -Dallegro_EXPORTS -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2  -W -Wall  -O2 -g -fPIC -I/.../allegro5-5.0.7/include -I/.../allegro5-5.0.7/build/include     -DALLEGRO_SRC  -DALLEGRO_LIB_BUILD -o CMakeFiles/allegro.dir/src/file_stdio.c.o   -c /.../allegro5-5.0.7/src/file_stdio.c
/usr/bin/cmake -E cmake_progress_report /.../allegro5-5.0.7/build/CMakeFiles 
/.../allegro5-5.0.7/src/file_stdio.c: In function 'al_make_temp_file':
/.../allegro5-5.0.7/src/file_stdio.c:304:18: error: 'PATH_MAX' undeclared (first use in this function)
/.../allegro5-5.0.7/src/file_stdio.c:304:18: note: each undeclared identifier is reported only once for each function it appears in
/.../allegro5-5.0.7/src/file_stdio.c:304:9: warning: unused variable 'filename' [-Wunused-variable]
make[3]: *** [CMakeFiles/allegro.dir/src/file_stdio.c.o] Error 1
make[2]: *** [CMakeFiles/allegro.dir/all] Error 2
make[1]: *** [all] Error 2
dh_auto_build: make -j1 returned exit code 2
make: *** [build-arch] Error 2
dpkg-buildpackage: error: debian/rules build-arch gave error exit status 2

Could you please supply a fallback definition if necessary, say 4096?

Thanks!