Ignore log files that appear in root dir with "spack -d install ..."

[scottwittenburg]

I noticed recently that when I install packages with the -d option, I have started getting a bunch of log files in the root directory of the repository:

$ git status
On branch develop
Your branch is up-to-date with 'origin/develop'.
Untracked files:
  (use "git add <file>..." to include in what will be committed)

	spack-cc-binutils-4an3yhe.in.log
	spack-cc-binutils-4an3yhe.out.log
        ...

This PR make sure that git ignores those to avoid cluttering up status output.

[davydden]

I don't know the internals of install, but most likely there is a bug somewhere that ought to be fixed so that those files do not appear in the first place.

[alalazo]

@davydden Those files are, as far as I remember, written by the compiler wrappers. I think the rationale is that injected flags - like RPATHs and such - don't appear in the logs, as they are internal to the wrapper. When you activate debugging the compiler wrapper writes in a file, like spack-cc-binutils-4an3yhe.in.log, what it received in input and in another what it actually executed.

[davydden]

i see, thanks for explanation

[alalazo]

@tgamblin @scheibelp I am going to merge this