[swift-evolution] Draft Proposal SwiftPM System Module Search Paths

[Colin Barrett]

On Mar 24, 2016, at 5:55 PM, Max Howell <max.howell at apple.com> wrote:

>> Thanks for sending out this proposal. I admit I’m somewhat ignorant of the current state of SwiftPM so feel free to point me at existing resources if I’m missing basic things.
>> 
>> You don’t cover it in your proposal, but does this mean pkg-config is now a dependency for SwiftPM? I may be mistaken but it doesn’t seem as though pkg-config is installed on the base OS X system. (This leads me to assume it’s an optional dependency.)
> 
> This is a good point, I’ll revise the proposal.
> 
> My intentions were: if available, use it, if not, then things may not build. Long term we could parse pkg-config files ourselves since the format is very basic which would be preferable since “your package graph *may* or *may not* build” is hardly fun

Great! Myself, I would just parse the pc files straight away. Avoiding dependencies seems  highly desirable for something this low in the stack.

>> Your proposal suggests the set of supported package mangers will be closed. What about folks using new, or non-standard package managers?
> 
> They can add their package manager to the supported list via a Pull Request.

This is a surprising answer! Just to be clear―what functionality, specifically, is this enabling?

>> What about packages that are installed system-wide without a package manager (e.g. with ./configure && make && make install)? 
> 
> Such packages should come with a .pc file.
> 
>> This may be covered elsewhere, but about the case of a C package that is normally system-wide but is currently being hacked on by the user? (For example to while debugging it, or writing bindings for it.)
> 
> There is no convenient way to do this at this time, but proposals are welcome. It *is* possible currently, you can make a local module map package that encapsulates the C library, or if it is simple enough our C-target support may be sufficient

No proposal here, but this is more common than you'd think―it merits at least an FAQ in the final proposal.

Thanks Max!
-Colin