Bump to chisel 6 release

[kammoh]

Hi,
I'm trying to help with expediating a chiseltest 6.0.0 release as 6.0-SNAPSHOT does not work with the chisel-6.0.0 release.
I also noticed the Verilator coverage support was broken with Verilator versions >= 5.012 (and probably >=5).
Tested only on macOS. All tests (excluding VCS backend, but including Verilator, Icarus, and formal) pass. Tests were run as:
sbt "testOnly chiseltest.** -- -l RequiresVcs"

Please let me know if any changes are required or otherwise free to make any modifications.

Summary of changes:

• Bumped chisel -> 6.0.0
• Fixed missing (moved) 'Width' class
• Bumped scala -> 2.13.12
• Fixed compilation issues due to 'scala.io' namespace clash
• bump sbt -> 1.9.8
• fix Verilator 5.x coverage
• fix Verilator 5.x tests

[ekiwi]

Two small things that need to be addressed. Otherwise, this is awesome! Thanks a lot!

[ekiwi]

This looks great! Will merge once all the tests pass.

I will try to make a 6.0.0 release of chiseltest soon.

[ekiwi]

The failures in the formal tests are because of a new ConstType: chipsalliance/chisel@b55bfd0

I think we could probably just drop that info for now.

The sbt test on mac that is failing might be sporadic. I will restart it soon

[kammoh]

The link to the issue on the last commit comment should be -> verilator/verilator#2505
Edit:
In short due to bison changes we won't be able to test verilator versions prior to 4.040 on Ubuntu 22.04.

[kammoh]

I sometimes see the exception on actual tests on mac. I'm not really familiar with the internals of the new schedular. Is there an easy way to fix it?

[ekiwi]

I sometimes see the exception on actual tests on mac. I'm not really familiar with the internals of the new schedular. Is there an easy way to fix it?

That would probably take me a day or two and I don't really have that time right now. I will try to think about whether there is a quick workaround.

[kammoh]

That would probably take me a day or two and I don't really have that time right now. I will try to think about whether there is a quick workaround.

It's ok with me if you'd rather hold back for the 6.0.0 release to include that fix, but in that case would it be possible to have a 6.0-SNAPSHOT release with these changes sooner?

[ekiwi]

It's ok with me if you'd rather hold back for the 6.0.0 release to include that fix, but in that case would it be possible to have a 6.0-SNAPSHOT release with these changes sooner?

Yes. Once you fix the failure of the formal testsuite by dealing with the ConstType I will try to find a workaround.

[kammoh]

Thanks!

[kammoh]

I couldn't find much documentation on ConstType but it seems it should be safe to just take and convert the inner type. All tests pass with this workaround.

[ekiwi]

I couldn't find much documentation on ConstType but it seems it should be safe to just take and convert the inner type

Thanks! I think so, too.

[ekiwi]

Could you move the Verilator 5 CI tests to a separate PR? Seems like they are timing out right now and there is no reason they should keep this PR from getting merged. Thanks!

[kammoh]

Typo in comment (should be "remove") but I'm leaving it for now. It would be great if you could fix it on merge.

[ekiwi]

Thanks!