Nix environment is broken on macos

[gracicot]

I wanted to test locally my changes for a future pull request and the nix environment seems broken on MacOS. Here's the output of running nix-shell:

building '/nix/store/d3k1zgccyykrxnsxzwzzkhn871808cah-breathe-5074aecb5ad37bb70f50216eaa01d03a375801ec-src.drv'...
dyld: Library not loaded: /usr/lib/system/libsystem_network.dylib
  Referenced from: /nix/store/zdh6jqgv3ayqgl0ifj1z3f9n4s31d8s4-Libsystem-osx-10.11.6/lib/libSystem.B.dylib
  Reason: image not found
error: builder for '/nix/store/d3k1zgccyykrxnsxzwzzkhn871808cah-breathe-5074aecb5ad37bb70f50216eaa01d03a375801ec-src.drv' failed due to signal 6 (Abort trap: 6);
       last 3 log lines:
       > dyld: Library not loaded: /usr/lib/system/libsystem_network.dylib
       >   Referenced from: /nix/store/zdh6jqgv3ayqgl0ifj1z3f9n4s31d8s4-Libsystem-osx-10.11.6/lib/libSystem.B.dylib
       >   Reason: image not found
       For full logs, run 'nix log /nix/store/d3k1zgccyykrxnsxzwzzkhn871808cah-breathe-5074aecb5ad37bb70f50216eaa01d03a375801ec-src.drv'.
error: 1 dependencies of derivation '/nix/store/sqf2k7cnwvqx4xq560bzlqq60z5csc7i-python2.7-breathe-git-arximboldi-5074aecb5ad37bb70f50216eaa01d03a375801ec.drv' failed to build
building '/nix/store/vp7b1p14phwkmjr047p4cr5m9vllkqz2-builder.pl.drv'...
error: 1 dependencies of derivation '/nix/store/rqkgr243m22d1jwr63q0j3x3d1gwr2zl-python-2.7.13-env.drv' failed to build
error: build of '/nix/store/575h7cmv25ijxmgip8sib2rgj27566l1-python3-3.8.5-env.drv', '/nix/store/71jgz7sv8vf3aa610pqq84b3xzbcq00f-sass-3.7.4.drv', '/nix/store/724fjxn5fgf7idlr15qdn11xqwrswr0h-immer-git-ffbc180da6463f8f06af0e96336f161256422b1f.drv', '/nix/store/dbcwi7vsnrvhbi0zph1wqhjg9qhchvz1-imgui-git-6ffee0e75e8f677c5fd8280dfe544c3fcb325f45.drv', '/nix/store/g4c95hwxzjyn58prg82a3vqwcxnf8iih-emscripten-2.0.1.drv', '/nix/store/hnhv3xk7m2rmi4g7q6959a38hrpsw5dh-cereal-git-arximboldi-f158a44a3277ec2e1807618e63bcb8e1bd559649.drv', '/nix/store/nqw5amnsd1py1w56q904rm8qi0srsb3r-libhttpserver-git-f4caf637090b5ff39bfc146b0ecd633f670c3697.drv', '/nix/store/rqkgr243m22d1jwr63q0j3x3d1gwr2zl-python-2.7.13-env.drv', '/nix/store/wyscvqk5z25v2di15jzvvcvj7qh2gnfh-zug-git-be20cae36e7e5876bf5bfb08b2a0562e1db3b546.drv' failed

It seems that the breathe library build is broken.

[gracicot]

Wrong repo