intellisense performance poor in Omnisharp 1.37.2

[devhawk]

VSCode on my machine updated to Omnisharp 1.37.2 this afternoon. Intellisense performance has fallen off a cliff. Operations that were instant before are now taking upwards of 10 seconds, making intellisense shortcuts basically unusable.

is there some type of log I can capture to assist in debugging?

[filipw]

did you upgrade from 1.37.1 to 1.37.2 or from some other version? there were no major changes to completion in 1.37.2.

you can set omnisharp.loglevel: "trace" in settings and capture the log from omnisharp log panel but it doesn't contain any timings. it would be best if you could share the affected project - is this on every project type that you experience this or just on a specific one?

[devhawk]

I didn't manually upgrade, I just noticed that the vscode extension was updating omnisharp, so I'm not sure what version it was upgrading from.

I'm only working on one project right now, I can check other projects tomorrow. This is the project / branch that I noticed the issue: https://github.com/neo-project/neo-express/tree/devhawk/nxp

[filipw]

thanks, you are right, I can repro this using the project you link on a Mac (on Windows it performs very good).

@JoeRobich @333fred any ideas?
for example on this line https://github.com/neo-project/neo-express/blob/master/src/neo-express/BlockchainOperations.cs#L38 typing wallets. and then pressing cmd+space, it takes forever for the completion list to be populated. this happens with import completions switched off too

[devhawk]

thanks, you are right, I can repro this using the project you link on a Mac (on Windows it performs very good).

FWIW, I'm using windows

[filipw]

actually you are right.

looks like it was regressed by #1962

Switching to "omnisharp.path": "1.37.2-beta.105" still has good performance, and there is only #1970 (which is LSP specific so not related) and #1962 between 1.37.2-beta.105 and 1.37.2.

[filipw]

1.37.2-beta.105

1.37.2

[333fred]

Are you sure you mean #1962? Did we already do a release with that in it?

[david-driscoll]

Yeah we just released v1.37.2

[333fred]

Hmm. I can try to take a look, but there being a completion regression there surprises me. It doesn't even touch that area.

[jannickj]

I am seeing the same :(

[filipw]

it looks like the regression is on codecheck which then impacts the completion
I believe this issue, dotnet/vscode-csharp#4111 and #1983 all have the same root cause

[333fred]

@filipw I can do a targeted revert tonight: I'll bring the old caching behavior back, and make the fixall service not depend on the analyzer diagnostic worker for diagnostics in a different way. However, this implies that completion itself may have bugs where it's not using up-to-date semantic info. I'm not sure how that would manifest exactly, but there's likely something.

[filipw]

thank you! we need to invest in performance testing 😩