sync errorgroup: producing a better failure message for a programmer error

SetLimit(10) Go(xx) //start a groutine ,g.done be called if task done SetLimit(-1) //<-- g.sem=nil

but g.done is not atomic, if g.sem=nil maybe block the goroutine

Jun 18 '22 11:06 shifengbin

This PR (HEAD: 51b70160499559410eebe1a97d750e29086949bc) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/sync/+/413094 to see it.

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Jun 18 '22 11:06 gopherbot

Message from Ian Lance Taylor:

Patch Set 1:

(2 comments)

Please don’t reply on this GitHub thread. Visit golang.org/cl/413094. After addressing review feedback, remember to publish your drafts!

Jun 18 '22 23:06 gopherbot

Message from fengbin shi:

Patch Set 1:

(2 comments)

Please don’t reply on this GitHub thread. Visit golang.org/cl/413094. After addressing review feedback, remember to publish your drafts!

Jun 19 '22 01:06 gopherbot

Message from Bryan Mills:

Patch Set 1:

(3 comments)

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Jun 21 '22 19:06 gopherbot

Message from fengbin shi:

Patch Set 2:

(2 comments)

Please don’t reply on this GitHub thread. Visit golang.org/cl/413094. After addressing review feedback, remember to publish your drafts!

Jun 22 '22 02:06 gopherbot