For a given conda package, how to I list the packages that depend on it?
I recently installed anaconda on a university cluster that already had a version of MPI (openmpi). The mpich2 package and mpi4py packages installed with anaconda were fine for demos of mpi4py, but the mpi* compilers (mpicc, etc) were not compatable. So I conda remove'd mpich2 and mpi4py and used pip to install mpi4py using the local MPI install and compilers.
I had to dig around to find mpi4py's dependencies and then mpich2's dependents, for which I only identified mpi4py. Is there an "easy" way to find out what depends on mpich2?
Searching the package cache will only show you the packages that you have downloaded already. For your case, this behavior is fine, but if you want to know every package that depends on a given package, a better way is to search the repodata of your channels. The repodata is cached in ~/anaconda/pkgs/cache, or you can navigate with your browser to http://repo.continuum.io/pkgs/free/ and click on repodata.json for the platform you use (for Binstar, go to, e.g., https://conda.binstar.org/asmeurer). Then search for the name of the package in the "depends" key.