cut: -d= works differently than gnu-cut

[SuperSandro2000]

gnu-cat:

echo "--libdir=./out/lib" | cut -f2 -d=
./out/lib

uutils-cat:

echo "--libdir=./out/lib" | result/bin/cut -f2 -d"="
--libdir=./out/lib

Noticed while building rustc.

[jhscheer]

This seems to be a limitation of the parsing done by the clap crate.
In their docs it says:

NOTE: values for arguments may be specified in any of the following methods
Using a space such as -o value or --option value
Using an equals and no space such as -o=value or --option=value
Use a short and no space such as -ovalue

If the method is a short and no space, the value can't be =.
Right now, to use = as delimiter for cut, there has to be a space, i.e. only -d = and --delimiter = works.

[SuperSandro2000]

Isn't there an effort to migrate away from clap?

I can't and don't really want to change the installer script for rust to be compatible with uutils-coreutils. https://github.com/rust-lang/rust-installer/blob/master/install-template.sh#L179

[tertsdiepraam]

Quite the opposite 😄 We've been moving utils to clap. I agree however that we should support this. I see two paths forward (1) we work around clap or (2) we contribute a new setting to clap that disables this behaviour. I would prefer the second option, but we'll have to wait for clap 3 to be able to use it.

[jhscheer]

I prefer (1).
I briefly glanced over clap 3beta and the clap discussions and didn't see this issue mentioned.
Also there's no clear ETA when clap 3 will be stable, it could very well take another 6-12 months.

[tertsdiepraam]

Agreed, my preference was more "in an ideal situation". I'm not quite sure how to work around it in this case, though, but it's probably possible.

Might still be worth contributing to clap in the long term. They seem to welcome PR's even if they weren't discussed at length. I contributed InferLongArgs this way.