Buggy -- intermittent missing package updates

[CameronNemo]

Official void-updates text report for 2020-12-06 is missing slirp4netns, but when I manually run ./xbps-src update-check slirp4netns I see an update is available. no changes to that package have occurred prior to December.

I believe this is related to the behavior I am seeing when manually running ./xbps-src update-check with xargs:

$ printf 'R-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\nR-cran-nloptr\n' | xargs -I{} -P20 ./xbps-src update-check {}
NO VERSION found for R-cran-nloptr
NO VERSION found for R-cran-nloptr

That runs several (way more than 2) instances of update-check, but only two runs produce the NO VERSION found error.

Not sure whether to report this here (void-updates) or in xbps-src / void-packages.