Eigen assumes that CMAKE_INSTALL_INCLUDEDIR is a path relative to
CMAKE_INSTALL_PREFIX (typically "include"), but CMake supports it being an
absolute path, which is the case in Nixpkgs. This resulted in EIGEN3_INCLUDE_DIR
being set to "/nix/store/…eigen…//nix/store/…eigen…/include/eigen3".
GNUInstallDirs_get_absolute_install_dir requires CMake 3.7.
* treewide: http -> https sources
This updates the source urls of all top-level packages from http to
https where possible.
* buildtorrent: fix url and tab -> spaces
Semi-automatic update generated by https://github.com/ryantm/nix-update tools. These checks were done:
- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 3.3.4 with grep in /nix/store/q5xnlq781hvj0skjlhnb1qw1k69pf048-eigen-3.3.4
- directory tree listing: https://gist.github.com/d83ce54c91cb6ecf3fd3eb94b666357f