I am trying to build https://github.com/mltframework/shotcut on OS X Lion (using their script in scripts/build_shotcut.sh) and after numerous hurdles I'm stuck on this error:

./configure: line 16062: syntax error near unexpected token `OPENCV,'
./configure: line 16062: `PKG_CHECK_MODULES(OPENCV, opencv >= 1.0.0, HAVE_OPENCV=true, true)'
ERROR: Unable to configure frei0r

From what I already googled this means that the PKG_CHECK_MODULES macro hasn't been defined, which probably means there's something wrong with my pkg-config, which I installed via Homebrew. Sounds like the pkg.m4 file isn't found.

When I brew install pkg-config I get the following warning:

Warning: m4 macros were installed to "share/aclocal".
Homebrew does not append "/usr/local/share/aclocal"
to "/usr/share/aclocal/dirlist". If an autoconf script you use
requires these m4 macros, you'll need to add this path manually.

Well I've appended that line to the dirlist file and it doesn't fix the problem above.

Can anyone suggest a way forward here?

I have briefly tried building my own pkg-config from source but (bizarrely) when I tried to ./configure I got the following error:

checking for pkg-config... no
./configure: line 13540: --exists: command not found
configure: error: pkg-config and glib-2.0 not found, please set GLIB_CFLAGS and GLIB_LIBS to the correct values

if building pkg-config needs pkg-config it seems like a weird catch 22 situation... I think this is probably an unnecessary sidetrack anyway.