I was trying to install tcoq and gamepad as described here but had the errors:
make
/Library/Developer/CommandLineTools/usr/bin/make --warn-undefined-variable --no-builtin-rules -f Makefile.build
OCAMLC -c -pp grammar/gramCompat.mlp
>> Fatal error: OCaml and preprocessor have incompatible versions
Fatal error: exception Misc.Fatal_error
make[1]: *** [grammar/gramCompat.cmo] Error 2
make: *** [submake] Error 2
so I discovered that I had the wrong version of campl5
:
$ camlp5 -v
Camlp5 version 7.07 (ocaml 4.07.0)
since the one I need is the one compatible with ocaml 4.05.0
according to gamepad and tcoq.