Estoy tratando de instalar GraphicsMagick en Mountain Lion y tengo problemas. Probé todas las cosas que podía buscar en blogs y otras preguntas de stackoverflow pero nada funcionó. Así que he puesto la pila completa de errores que recibo en cada comando. Por favor, mira y ayúdame.

Cuando corro

brew install graphicsmagick

entiendo esto

Warning: Could not link jpeg. Unlinking...
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
You can try again using `brew link jpeg'

y

Warning: Could not link libpng. Unlinking...
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
You can try again using `brew link libpng'

y en el ultimo me estoy poniendo

==> make install
Warning: Could not link graphicsmagick. Unlinking...
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
You can try again using `brew link graphicsmagick'

Possible conflicting files are:
==> Summary
  /usr/local/Cellar/graphicsmagick/1.3.18: 283 files, 10M, built in 52 seconds

Ahora si intentobrew link jpeg obrew link libpng Me sale este error

Linking /usr/local/Cellar/jpeg/8d... Warning: Could not link jpeg. Unlinking...

Error: Could not symlink file: /usr/local/Cellar/jpeg/8d/bin/wrjpgcom
Target /usr/local/bin/wrjpgcom already exists. You may need to delete it.
To force the link and overwrite all other conflicting files, do:
  brew link --overwrite formula_name

To list all files that would be deleted:
  brew link --overwrite --dry-run formula_name

Si intento el método de sobrescritura haciendobrew link --overwrite jpeg funcionó. Pero 'brew link --overwrite libpng' Entiendo esto

Linking /usr/local/Cellar/libpng/1.5.14... Warning: Could not link libpng. Unlinking...

Error: Permission denied - /usr/local/share/man/man5/png.5

Y después de eso cuando lo intente.brew link graphicsmagick Yo obtengo:

Linking /usr/local/Cellar/graphicsmagick/1.3.18... Warning: Could not link graphicsmagick. Unlinking...

Error: Could not symlink file: /usr/local/Cellar/graphicsmagick/1.3.18/share/man/man5/quantize.5
/usr/local/share/man/man5 is not writable. You should change its permissions.

Por favor, ayúdame. Gracias por adelantado.