expat: new recipe (git dependency)

[frol]

Expat is an XML parser library written in C. It is a stream-oriented parser in which an application registers handlers for things the parser might find in the XML document (like start tags).

You can test this package by installing it from salford_systems channel:

$ conda install -c salford_systems expat

Package on Anaconda.org: https://anaconda.org/salford_systems/expat

[msarahan]

Is GCC a strict requirement, or can it be compiled with, for example, clang? Any tips on why GCC might be an explicit requirement?

[frol]

@msarahan I haven't tried clang. I have successfully built this package for linux-32, linux-64, and osx-64 as it is now. I just prefer to use as much conda dependecies as possible instead of relying on system-wide packages.

[ccordoba12]

Missing run: with libgcc, right?

[frol]

@ccordoba12 You may add it there if you like, but it is not needed there.

[ccordoba12]

I don't feel comfortable about not adding it. It has been our custom to always add libgcc when we demand gcc. Or not use gcc at all (as Mike suggested above).

[frol]

@ccordoba12 I don't get the logic at all. System-wide packages are less reliable than conda dependency, but you suggest to choose between (1) loosing gcc dependency or (2) adding the unnecessary libgcc dependency for the sake of "custom". Python is built with gcc, isn't it? Still, it doesn't require libgcc.

[ccordoba12]

Nop, Python is not built with gcc. It's built with the gcc that comes in CentOS 5. We really use gcc for very few packages (the R ones mostly). So until now we've demanded libgcc as a run dep whenever we use gcc as a build dep.

But perhaps that's only necessary when building C++ libraries instead of C ones (because the C standard is much more stable).

@asmeurer, could you clarify when it's necessary to use libgcc?

[frol]

I have just removed the gcc dependency.

[ccordoba12]

@msarahan, merging?

[msarahan]

Thanks!