Hello Galaxy-devs, I am setting up galaxy on current os x 10.11 and encounter this trouble using galaxy to install pixman-0.32.4: the package gets downloaded successfully from http://cairographics.org/releases/pixman-0.32.4.tar.gz <http://cairographics.org/releases/pixman-0.32.4.tar.gz> … while following the installation process in terminal I see this output during the process …presumably indicating an gcc problem ... install_environment.STDOUT DEBUG 2015-12-01 10:44:18,096 checking build system type... x86_64-apple-darwin15.0.0 install_environment.STDOUT DEBUG 2015-12-01 10:44:18,099 checking for gcc... gcc checking build system type... x86_64-apple-darwin15.0.0 checking host system type... x86_64-apple-darwin15.0.0 checking for gcc... gcc checking whether the C compiler works... no configure: error: in `/Users/hans/galaxy/database/tmp/tmp-toolshed-mtdKC9F_F/pixman-0.32.4': configure: error: C compiler cannot create executables See `config.log' for more details Curiously, if I download the pixman package (same URL) outside of galaxy and run ./configure … gcc seems to work : ... checking build system type... x86_64-apple-darwin15.0.0 checking host system type... x86_64-apple-darwin15.0.0 checking for gcc... gcc checking whether the C compiler works… yes ... and ./configure finishes OK. to actually compile/make pixman properly, I have to use the ./configure —disable-mmx option to avoid another known error (pixman-mmx.c:100:20: error: constraint 'K' expects an integer constant expression : "y" (__A), "K" (__N)) Perhaps someone is using galaxy on Mac OS X how this difference in gcc handling arises? Thanks very much, Hans Rudolph