Hi!  This package has what appears to be a flaky test FTBFS, blocking
testing migration for other packages.

https://ci.debian.net/packages/g/golang-github-jbenet-go-context/testing/s390x/74314472/#L621

 61s === RUN   TestWithParentsMany
 61s     dagctx_test.go:95: deadline - now: 1.999993345s
 61s     dagctx_test.go:95: deadline - now: 1.999994041s
 61s     dagctx_test.go:95: deadline - now: 1.999995306s
 61s     dagctx_test.go:95: deadline - now: 3.99999334s
 61s     dagctx_test.go:95: deadline - now: 4.999992415s
 61s     dagctx_test.go:95: deadline - now: 1.99998906s
 61s     dagctx_test.go:95: deadline - now: 1.999985867s
 61s     dagctx_test.go:95: deadline - now: 1.999994358s
 61s     dagctx_test.go:95: deadline - now: 2.999991322s
 61s     dagctx_test.go:95: deadline - now: 3.99999328s
 61s     dagctx_test.go:95: deadline - now: 1.999987892s
 61s     dagctx_test.go:95: deadline - now: 2.999985461s
 61s     dagctx_test.go:95: deadline - now: 2.999986894s
 61s     dagctx_test.go:95: deadline - now: 2.999990526s
 61s     dagctx_test.go:95: deadline - now: 4.999984775s
 61s     dagctx_test.go:95: deadline - now: 1.999988272s
 61s     dagctx_test.go:95: deadline - now: 6.999979665s
 61s     dagctx_test.go:95: deadline - now: 7.999984281s
 61s     dagctx_test.go:95: deadline - now: 3.999988833s
 61s     dagctx_test.go:95: deadline - now: 1.999985562s
 61s     dagctx_test.go:95: deadline - now: 1.999980825s
 61s     dagctx_test.go:95: deadline - now: 2.999985877s
 61s     dagctx_test.go:95: deadline - now: 1.999980315s
 61s     dagctx_test.go:95: deadline - now: 1.99998229s
 61s     dagctx_test.go:95: deadline - now: 1.999987308s
 61s     dagctx_test.go:95: deadline - now: 1.999978248s
 61s     dagctx_test.go:95: deadline - now: 1.99997342s
 61s     dagctx_test.go:95: deadline - now: 4.999975727s
 61s     dagctx_test.go:95: deadline - now: 1.999968138s
 61s     dagctx_test.go:95: deadline - now: 3.99997442s
 61s     dagctx_test.go:95: deadline - now: 4.999979197s
 61s     dagctx_test.go:95: deadline - now: 1.999975784s
 61s     dagctx_test.go:95: deadline - now: 1.999971773s
 61s     dagctx_test.go:95: deadline - now: 4.999978571s
 61s     dagctx_test.go:95: deadline - now: 3.999972285s
 61s     dagctx_test.go:95: deadline - now: 2.999969683s
 61s     dagctx_test.go:95: deadline - now: 1.999974381s
 61s     dagctx_test.go:95: deadline - now: 2.999969115s
 61s     dagctx_test.go:95: deadline - now: 1.999979439s
 61s     dagctx_test.go:95: deadline - now: 1.999958857s
 61s     dagctx_test.go:95: deadline - now: 1.999978918s
 61s     dagctx_test.go:95: deadline - now: 2.999978314s
 61s     dagctx_test.go:95: deadline - now: 3.999977781s
 61s     dagctx_test.go:95: deadline - now: 1.999965965s
 61s     dagctx_test.go:95: deadline - now: 3.999972661s
 61s     dagctx_test.go:95: deadline - now: 5.999983049s
 61s     dagctx_test.go:95: deadline - now: 4.999974257s
 61s     dagctx_test.go:95: deadline - now: 1.999863097s
 61s     dagctx_test.go:95: deadline - now: 1.999969171s
 61s     dagctx_test.go:95: deadline - now: 1.999964019s
 61s     dagctx_test.go:95: deadline - now: 3.999968486s
 61s     dagctx_test.go:95: deadline - now: 6.999970663s
 61s     dagctx_test.go:95: deadline - now: 2.999953259s
 61s     dagctx_test.go:111: any should've cancelled it
 61s     dagctx_test.go:115: errors should match
 61s     dagctx_test.go:95: deadline - now: 1.999966883s
 61s     dagctx_test.go:95: deadline - now: 1.999960144s
 61s     dagctx_test.go:95: deadline - now: 1.999953744s
 61s     dagctx_test.go:95: deadline - now: 1.999954119s
 61s     dagctx_test.go:95: deadline - now: 1.999958684s
 61s     dagctx_test.go:95: deadline - now: 1.999957003s
 61s     dagctx_test.go:95: deadline - now: 1.999963039s
 61s     dagctx_test.go:95: deadline - now: 1.999955836s
 61s     dagctx_test.go:95: deadline - now: 7.999948689s
 61s     dagctx_test.go:95: deadline - now: 3.999958252s
 61s     dagctx_test.go:95: deadline - now: 1.99994964s
 61s     dagctx_test.go:95: deadline - now: 1.999915675s
 61s     dagctx_test.go:95: deadline - now: 4.999949618s
 61s     dagctx_test.go:95: deadline - now: 2.999933942s
 61s     dagctx_test.go:95: deadline - now: 3.999952443s
 61s     dagctx_test.go:95: deadline - now: 2.999958748s
 61s     dagctx_test.go:95: deadline - now: 1.999941055s
 61s     dagctx_test.go:95: deadline - now: 1.999936375s
 61s     dagctx_test.go:95: deadline - now: 1.999942127s
 61s     dagctx_test.go:95: deadline - now: 1.999941418s
 61s     dagctx_test.go:95: deadline - now: 1.999958565s
 61s     dagctx_test.go:95: deadline - now: 2.999963364s
 61s     dagctx_test.go:95: deadline - now: 1.999946485s
 61s     dagctx_test.go:95: deadline - now: 3.999962146s
 61s     dagctx_test.go:95: deadline - now: 1.999938484s
 61s     dagctx_test.go:95: deadline - now: 1.999920048s
 61s     dagctx_test.go:95: deadline - now: 1.999940867s
 61s     dagctx_test.go:95: deadline - now: 1.999940586s
 61s     dagctx_test.go:95: deadline - now: 1.999928341s
 61s     dagctx_test.go:95: deadline - now: 1.999931707s
 61s     dagctx_test.go:95: deadline - now: 4.999951604s
 61s     dagctx_test.go:95: deadline - now: 3.999948941s
 61s     dagctx_test.go:95: deadline - now: 2.999956067s
 61s     dagctx_test.go:95: deadline - now: 1.999941231s
 61s     dagctx_test.go:95: deadline - now: 1.999930919s
 61s     dagctx_test.go:95: deadline - now: 1.999942102s
 61s     dagctx_test.go:95: deadline - now: 3.999946611s
 61s --- FAIL: TestWithParentsMany (0.15s)
 61s FAIL
 61s FAIL	github.com/jbenet/go-context/dag	0.152s

/Simon