Hi, Thanks for the very quick response.
On my system, it is gsl/gsl_filter.h, rather than gsl/filter/gsl_filter.h . I'm not sure why - I'm running stable and have manually backported the testing release, as gsl_filter.h is new and I'm using it in my code. $ apt-file find gsl_filter.h libgsl-dev: /usr/include/gsl/gsl_filter.h I've raised the original concern upstream: https://savannah.gnu.org/bugs/index.php?54921 Just for reference - I thought that Debian policy was to report to Debian, and have the maintainer contact upstream? [1,2] Perhaps I am mistaken? Is it possible that this can be patched in Debian in the meantime, so others don't have this problem? I've fixed it locally, so I am fine. Thanks! [1] https://www.debian.org/Bugs/Reporting ("If necessary, the maintainer of the package will forward the bug upstream.") [2] https://wiki.debian.org/BugTriage#Forwarding_reports_upstream
