Hi there, I have two libraries that I'm working on, packageA and packageB. packageA was written some time ago and depends on a foreign C library, libfoo, which I also wrote and which is installed in a non-standard location. packageB depends on packageA and is new and under active development. I have the following things, then: - libfoo is installed in ~/.local/lib, with includes in ~/.local/include/foo - packageA is in ~/src/packageA - packageB is in ~/src/packageB packageA has a .cabal file which includes: library build-depends: base, ... exposed-modules: A include-dirs: /home/richard/.local/include extra-lib-dirs: /home/richard/.local/lib executable testA ... extra-lib-dirs: /home/richard/.local/lib extra-libraries: foo I've created a cabal sandbox in packageA and I can successfully build it. Now, packageB makes use of packageA. It has a .cabal file which looks like this: library build-depends: base, packageA, ... exposed-modules: B executable testB ... extra-lib-dirs: /home/richard/.local/lib extra-libraries: foo Again, I've created a cabal sandbox in packageB. In order to be able to use packageA (which is not installed anywhere) I believe I have to do: $ cabal add-source ~/src/packageA Next, when I try and configure, it says: cabal: At least the following dependencies are missing: packageA -any That's fine, I assume, because I can now just `cabal install --only-dependencies` to get packageA built into packageB's sandbox. But when I try and do this, I get: $ cabal install --only-dependencies Resolving dependencies... Configuring packageA-0.1... Building packageA-0.1... Preprocessing library packageA-0.1... In-place registering packageA-0.1... Preprocessing executable 'testA' for packageA-0.1... Foo.hsc:10:33: fatal error: foo/foo.h: No such file or directory compilation terminated. So a target of packageA which compiles fine when doing cabal build directly from packageA now fails to compile when I attempt to build it from packageB by installing packageB's dependencies. I'm not sure how to proceed. It feels like maybe I have to tell cabal--when running it from packageB--where the include files are for packageA, because packageA needs to get compiled (which involves linking against libfoo and using libfoo's includes). I know that packageA *does* compile (because I've done that already), but it won't compile inside packageB's sandbox. Any suggestions? Richard