Travis builds should work on OS X

[vermiculus]

Right now, evm install emacs-$VERSION-travis won't work on OS X containers. This is probably simply explained by the pre-built container being built for some Linux, not OS X.

If it's indeed not supported today, how would you expect it to be implemented? Would it be smarts within the recipe itself or would it be a separate recipe? (I'm not too familiar with EVM internals, but my guess is the former.)

[sambrightman]

Travis builds are intended for Linux. Build-from-source has always been supported on OS X but there are no prebuilt binaries (#17 was closed without solution). Under the current framework I'd expect a different recipe but issues like #120 may mean reconsidering how/what is prebuilt.

[doublep]

Can you please clarify this in README.md then? Right now it makes it look like Mac OS is as well supported as Linux, it is even enumerated higher.

[sambrightman]

I'm not 100% sure what is unclear - it doesn't seem reasonable to expect a single binary to work on different operating systems. OS X is indeed supported (from-source). I think the README was maybe adapted from a time where everything was from-source to focus more on pre-built CI (at the top of the file), so perhaps a clearer distinction between general EVM (tested and supported on both Linux and MacOS) and pre-built binaries for CI?

[doublep]

One might expect that EVM provides different binaries under the same name, depending on target OS. Or one might expect to do Travis testing on Mac OS, only to find out that EVM is not too useful for this (don't tell me I'm supposed to compile Emacs on Travis every time; locally it takes I don't know how long - maybe 10 or 15 minutes when executed in 4 parallel threads).

[sambrightman]

No one is telling you what you are supposed to do. I understand Travis has some caching abilities, maybe these could be used in the interim before you send your PR to help build Mac OS Travis binaries? (https://docs.travis-ci.com/user/caching/ I think).

Would the suggested README clarification be helpful?

[doublep]

before you send your PR to help build Mac OS Travis binaries

I don't have access to any Mac OS machine.

Would the suggested README clarification be helpful?

Suggested where?

I just think that instead of "Supported!" README should say something like "Supported! (But EVM currently doesn't provide any binaries for OSX.)". Basically, I think that a user that just comes to the site and Ctrl+F for "osx" shouldn't be left with the impression that OS X support is perfect and complete.