Hi,
I did that:
cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-raspberrypi.cmake
make
...
[ 33%] Linking CXX executable cosmic_protector
../../lib/liballegro.so.5.2.4: undefined reference to `glPopClientAttrib'
../../lib/liballegro.so.5.2.4: undefined reference to `glGetCompressedTexImage'
collect2: error: ld returned 1 exit status
version 5.2.2 work fine on same machine.
Should be fixed as of https://github.com/liballeg/allegro5/commit/95959418de5d5375a11a9b3bf2a94531fa1ac33a.
Thanks for reporting this!