Disable output colorization on terminals that don't support it

[fhars]

The current version of the colored crate ignores the capabilities of
the terminal (see colored-rs/colored#108),
which makes the outupt of probe-run unparseable in e.g. emacs
compilation mode. As a temporary workaround, this patch overrides
colorization if probe-run is called from a terminal without color
support.

[Urhengulas]

Hi @fhars, thank you for the patch. I tested it and it seems to work as expected. Can you please add the Cargo.lock file as well?

I have two concerns regarding the added terminfo dependency:

1. The maintenance of it seems to be currently unclear. See Maintainance of this crate meh/rust-terminfo#20. There are a few people interested in taking over maintenance, but it seems the handover didn't happen yet.
2. It adds outdated versions for a few dependencies, which some of them are already part of our dependency tree. This partially like a symptom of point 1.

I think it is reasonable to merge this PR anyways, but we should keep an eye on that and if it stays unmaintained eventually look for an alternative crate.

[jonas-schievink]

Does emacs' compilation mode present itself as a terminal (via isatty) to the program (I do hope we support non-isatty mode properly already, so perhaps it doesn't)? Does it set something like TERM=dumb that we could detect instead?

[Urhengulas]

Does emacs' compilation mode present itself as a terminal (via isatty) to the program (I do hope we support non-isatty mode properly already, so perhaps it doesn't)? Does it set something like TERM=dumb that we could detect instead?

From reading colored-rs/colored#108 I understood that it is setting TERM=dumb. But I don't know if this is the only trigger we want to look out for, or if there is other ones as well?

[Urhengulas]

@fhars Since it is a temporary fix until colored handles it properly, would it be enough for your purposes to only check TERM=dumb and disable coloring then?

[fhars]

That would fix the immediate use case of running it in a emacs compilation buffer, but the terminfo database on my system knows about 1332 kinds of terminal that do not have color support. (Although most of these are probably collectors items by now, it's decades since I have seen an operational tek4013).

And given that colored seems to be in deep hibernation for the last years, nothing may last as long as a stopgap measure.

[Urhengulas]

Superseded by #320