Set the environment variable to enable colorful output by default

Description:

.NET previously disabled console colors if it detected that the output was redirected. Recently, a new environment variable has been added to override this: https://github.com/dotnet/runtime/pull/47935

Setting below environment variables will enable colorful output when running on GitHub Actions (not on Windows though):

• DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION to 1 or true
• TERM to xterm

More info: https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-environment-variables#dotnet_system_console_allow_ansi_color_redirection

Relevant discussion explaining the need for the second variable: https://github.com/dotnet/runtime/discussions/68302#discussioncomment-2605104

Justification:

Colorful output is much easier to visually parse and, since we can guarantee that we’re always running on GitHub Actions (which supports ansi color escape codes), it makes sense to make this setting enabled by default. As the worst case, this should be at least added as one of the action inputs, but I think enabling it by default is the way to go (not anymore, read comments below).

Are you willing to submit a PR?

Sure

[xt0rted]

…there may be some edge-cases such as if some step relies on the output of a dotnet command to have a specific format…

This is actually the case with FORCE_COLOR in node with the setup-node action (ref: https://github.com/actions/setup-node/issues/317). When enabling that and using the cache option the post setup step fails because of the color codes in the log. The solution there is to disable that setting on the setup-node step, but it does catch you off guard if you don’t know about it.

[Tyrrrz]

@Tyrrrz, it seems to me the setting of these variables is out of scope setup-dotnet action cause it’s related to kind of customisation .NET installation but the goal of the action to install required .NET version with minimum custom configuration. It will be better the users will set these settings as workflow env variables from their side.

I understand your point, but here’s why I think it makes sense as an addition to setup-dotnet:

1. Colored output looks much nicer without any drawbacks. I can’t imagine a situation where a user may not want it.
2. The two environment variables (DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION and TERM) are used to convince dotnet that the output terminal/renderer supports color codes. This is always true in case with GitHub Actions.
3. Most users are not aware that this is an option that they can set at all. Putting it in setup-dotnet would guarantee that everyone gets it.

That said, there may be some edge-cases such as if some step relies on the output of a dotnet command to have a specific format (for example regex) that this option may break. Because of this, I now realize it’s probably not a great idea to have it enabled by default in those cases (unless with a major version bump?).

In any case, I leave the decision with you 😃 I’m personally okay setting this manually for my own projects.