So, after a long hiatus I updated CFFI, only to see dreaded compilation errors pop-up. Nothing better to keep me awake for an extra hour. The two patches (in the attached file) fix the error that I see and improve the code slightly. One patch removes ^M that CCL sees at the end of output of pkg-config. The need for the second patch arises in the case when the package loading fails, and I try to load it again. In that case *cc-flags* gets loaded with duplicate entries. This patch removes the duplicates. I generated the patches with the command: git format-patch master --stdout > mv-mods.txt If there is a better way to submit patches, let me know how and I will resend. Thanks, Mirko