> I even tried with a custom Is function defined, go vet check still fails. It seems to be the Error function that's significant to the linter here.
The linter is happy once your error type implements the error interface. Working example: https://go.dev/play/p/PzjXq1tfgLL On Friday, August 21, 2026 at 6:42:59 AM UTC-4 Steven Hartland wrote: > Workaround is to run go test with -vet=off > > On Fri, 21 Aug 2026 at 10:10, Steven Hartland <[email protected]> > wrote: > >> Go 1.27 made stdversion checks run by default when running go test as >> well as an extra check for errors.Is compatibility. This checks for >> non-pointer types which appears to break compatibility with existing code, >> you >> can see this here >> https://go.dev/play/p/2nXq9OWS-rf?v=goprev >> >> Under go 1.26 the errors.Is works as expected but under 1.27 you get a >> compile failure. >> >> If I remove the & so it operates on HTTPError >> <https://go.dev/play/p/wLq1L7GMFZn> and not *HTTPError as I believe is >> suggested by the vet check two of the tests fail as HTTPError is not >> comparable. >> >> I even tried with a custom Is function defined, go vet check still fails. >> >> Am I missing something, or is this a significant compatibility breakage >> introduced by 1.27? >> >> With & under 1.27 <https://go.dev/play/p/2nXq9OWS-rf> >> >> # [play] >> ./prog_test.go:27:44: %w wants operand of error type HTTPError, not pointer >> type *HTTPError (defeats errors.Is) >> Go build failed. >> >> >> Without & on 1.27 <https://go.dev/play/p/wLq1L7GMFZn> >> >> === RUN TestErrorsIs >> === RUN TestErrorsIs/wrapped-eof >> === RUN TestErrorsIs/wrapped-sentinel >> prog_test.go:37: wrapped: &fmt.wrapError{msg:"wrapped eof error: EOF", >> err:main.HTTPError{error:(*errors.errorString)(0x86ae60), StatusCode:404, >> Details:[]interface {}{"some extra info"}}} is not sentinel >> === RUN TestErrorsIs/direct-sentinel >> prog_test.go:42: sentinel: &fmt.wrapError{msg:"wrapped eof error: EOF", >> err:main.HTTPError{error:(*errors.errorString)(0x86ae60), StatusCode:404, >> Details:[]interface {}{"some extra info"}}} is not sentinel >> --- FAIL: TestErrorsIs (0.00s) >> --- PASS: TestErrorsIs/wrapped-eof (0.00s) >> --- FAIL: TestErrorsIs/wrapped-sentinel (0.00s) >> --- FAIL: TestErrorsIs/direct-sentinel (0.00s) >> FAIL >> Program exited. >> >> >> With & under 1.26 <https://go.dev/play/p/2nXq9OWS-rf?v=goprev> >> >> === RUN TestErrorsIs >> === RUN TestErrorsIs/wrapped-eof >> === RUN TestErrorsIs/wrapped-sentinel >> === RUN TestErrorsIs/direct-sentinel >> --- PASS: TestErrorsIs (0.00s) >> --- PASS: TestErrorsIs/wrapped-eof (0.00s) >> --- PASS: TestErrorsIs/wrapped-sentinel (0.00s) >> --- PASS: TestErrorsIs/direct-sentinel (0.00s) >> PASS >> >> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/golang-nuts/b7b31927-f85d-4008-b206-f92e4f6e8c70n%40googlegroups.com.
