cmd/go: TestScript/mod_sumdb_golang currently failing

[bcmills]

There is a new cmd/go failure in the longtest builder:
https://build.golang.org/log/6f541b96e3d3bd306c36aa040dc7341d544552ce

It is reproducible locally, but the first failure in the dashboard is at an unrelated CL. That suggests that something has changed in the interaction with the proxy: for some reason we're apparently needing to download additional checksum tiles.

--- FAIL: TestScript (0.00s)
    --- FAIL: TestScript/mod_sumdb_golang (9.24s)
        script_test.go:191: 
            # Test default GOPROXY and GOSUMDB (0.022s)
            # download direct from github (8.049s)
            # download from proxy.golang.org with go.sum entry already (1.151s)
            > go clean -modcache
            > env GOSUMDB=
            > env GOPROXY=
            > go get -x -d rsc.io/quote
            [stderr]
            # get https://proxy.golang.org/rsc.io/quote/@v/v1.5.2.mod
            # get https://proxy.golang.org/rsc.io/quote/@v/v1.5.2.mod: 200 OK (0.118s)
            # get https://proxy.golang.org/rsc.io/sampler/@v/v1.3.0.mod
            # get https://proxy.golang.org/rsc.io/sampler/@v/v1.3.0.mod: 200 OK (0.001s)
            # get https://proxy.golang.org/golang.org/x/text/@v/v0.0.0-20170915032832-14c0d48ead0c.mod
            # get https://proxy.golang.org/golang.org/x/text/@v/v0.0.0-20170915032832-14c0d48ead0c.mod: 200 OK (0.002s)
            # get https://proxy.golang.org/rsc.io/quote/@v/list
            # get https://proxy.golang.org/rsc.io/quote/@v/list: 200 OK (0.009s)
            go: finding rsc.io/quote v3.0.0+incompatible
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.info
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.info: 200 OK (0.005s)
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.mod
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.mod: 200 OK (0.079s)
            # get https://proxy.golang.org/sumdb/sum.golang.org/supported
            # get https://proxy.golang.org/sumdb/sum.golang.org/supported: 410 Gone (0.001s)
            # get https://sum.golang.org/tile/8/0/162.p/142
            # get https://sum.golang.org/tile/8/1/000.p/162
            # get https://sum.golang.org/tile/8/1/000.p/162: 200 OK (0.009s)
            # get https://sum.golang.org/tile/8/0/162.p/142: 200 OK (0.009s)
            # get https://sum.golang.org/lookup/rsc.io/[email protected]+incompatible
            # get https://sum.golang.org/lookup/rsc.io/[email protected]+incompatible: 200 OK (0.069s)
            # get https://sum.golang.org/tile/8/0/162.p/229
            # get https://sum.golang.org/tile/8/0/162.p/229: 200 OK (0.002s)
            go: downloading rsc.io/quote v3.0.0+incompatible
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.zip
            # get https://proxy.golang.org/rsc.io/quote/@v/v3.0.0+incompatible.zip: 200 OK (0.077s)
            go: extracting rsc.io/quote v3.0.0+incompatible
            go: downloading rsc.io/sampler v1.3.0
            # get https://proxy.golang.org/rsc.io/sampler/@v/v1.3.0.zip
            # get https://proxy.golang.org/rsc.io/sampler/@v/v1.3.0.zip: 200 OK (0.001s)
            go: extracting rsc.io/sampler v1.3.0
            go: downloading golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
            # get https://proxy.golang.org/golang.org/x/text/@v/v0.0.0-20170915032832-14c0d48ead0c.zip
            # get https://proxy.golang.org/golang.org/x/text/@v/v0.0.0-20170915032832-14c0d48ead0c.zip: 200 OK (0.019s)
            go: extracting golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c
            > ! stderr github
            > stderr proxy.golang.org/rsc.io/quote
            > ! stderr sum.golang.org/tile
            FAIL: testdata/script/mod_sumdb_golang.txt:26: unexpected match for `(?m)sum.golang.org/tile` found in stderr: sum.golang.org/tile
            
FAIL
FAIL	cmd/go	230.892s
FAIL

CC @rsc @FiloSottile @heschik @hyangah @katiehockman @jayconrod

[bcmills]

We've got a root cause, I think. I accidentally requested rsc.io/quote v3.0.0+incomptable from the proxy earlier today, which it fulfilled due to #32805 and ended up adding to the @v/list output.

That means that the go get -d rsc.io/quote in the test is now fetching v1.5.2 (correctly) with GOPROXY=direct, and v3.0.0+incompatible with GOPROXY set to the default.

[bcmills]

I'll fix the test to avoid the dependency on the contents of https://proxy.golang.org/rsc.io/quote/@v/list.

[gopherbot]

Change https://golang.org/cl/184719 mentions this issue: cmd/go: fix TestScript/mod_sumdb_golang to avoid assumptions about @v/list