SIGSEGV/nil pointer dereference when running dep ensure -update -dry-run

[na--]

What version of dep are you using (dep version)?

v0.4.1-256-g35c32f03 (via go get -u github.com/golang/dep/cmd/dep)

What dep command did you run?

I ran dep ensure -update -dry-run. See the attached log file or this CircleCI build.

What did you expect to see?

Everything running without errors

What did you see instead?

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x38 pc=0x80e592]

goroutine 1 [running]:
github.com/golang/dep.(*DeltaWriter).PrintPreparedActions(0xc42056fbc0, 0xc4200b7090, 0xc420312601, 0xc420d2fb0f, 0xc420216b40)
	/home/go/src/github.com/golang/dep/txn_writer.go:700 +0x3d2
main.(*ensureCommand).runUpdate(0xc4201ad950, 0xc4200d6980, 0xc4200b7030, 0x0, 0x0, 0xc4200f6090, 0x9fc240, 0xc4200c24e0, 0xc420024004, 0x28, ...)
	/home/go/src/github.com/golang/dep/cmd/dep/ensure.go:390 +0x457
main.(*ensureCommand).Run(0xc4201ad950, 0xc4200d6980, 0xc4200b7030, 0x0, 0x0, 0x0, 0x0)
	/home/go/src/github.com/golang/dep/cmd/dep/ensure.go:216 +0x7a9
main.(*Config).Run(0xc4200c2f60, 0x0)
	/home/go/src/github.com/golang/dep/cmd/dep/main.go:243 +0x1114
main.main()
	/home/go/src/github.com/golang/dep/cmd/dep/main.go:70 +0x52c

Connected issues and PRs

Those seem related:

• Dep ensure panics, but works when -v is included #1930
• Vendor verification #1912

[sdboyer]

ack! Sorry, looks like our tests missed a path. Fixing it now.

[na--]

Thanks!