Terminal colors for output #636
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If stderr isatty (i.e. the output is not being pumped to a file) and `$NO_COLOR` is unset or empty, or if `$FORCE_COLOR` is set and non-empty, output is colored. This helps distinguish `cabal2nix`'s output from the output of the fetchers it runs.
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Good idea, I think this is a good migitation for the error message problem the current fetcher logic has! Not quite sure what to think about colored output, i.e. if the extra code is worth it… |
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@sternenseemann Happy to remove the colored output if you'd prefer (or you can update my branch -- just drop the last commit), let me know |
sternenseemann
changed the title
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I've merged those changes manually, we can leave this PR for the color changes. I'm going to keep thinking about it. Maybe @maralorn and @cdepillabout want to comment? |
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I think I'm generally in favor of (optional) colors. For CLI programs that use color, I think I'd also expect a @9999years could you post a screenshot of what the colors look like in the output of cabal2nix? |
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@cdepillabout Added a screenshot to the PR description! |
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I think the colors seems nice, and it will likely make visually parsing the output of |
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Unsurprisingly I am all in favor of colorful output. Code complexity seems manageable. |
This adds terminal colors to
cabal2nix's output. This checks ifstderrisattyso that output will not be colored if (for example)cabal2nix'sstderris being piped to a file. It also respects the$NO_COLORand$FORCE_COLORenvironment variables for toggling the output coloring (see no-color.org).A couple small changes while I was preparing this:
nix-prefetch-scriptsto theshell.nixso that you can runcabal2nixsuccessfully while hacking on it.nix-prefetch-git ...) before we run it. This makes it a lot clearer where the errors come from, and which errors are being ignored (because we're trying another fetcher).Example output:
