dep init/ensure hangs when hg not found

[icio]

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

Built from source:

$ go version
go version go1.9.1 darwin/amd64

$ cd $GOPATH/src/github.com/golang/dep && git describe --tags
v0.4.1-37-g70b4da73

What dep command did you run?

Context:

$ pwd
/Users/icio/go/src/github.com/icio/dep-ensure-hang-repro

$ ls
main.go

$ cat main.go
package main
import "bitbucket.org/zombiezen/gopdf/pdf"
func main() { pdf.New() }

✅ Works:

$ which go git hg
/usr/local/go/bin/go
/usr/local/bin/git
/usr/local/bin/hg

$ dep init -v
Getting direct dependencies...
Checked 1 directories for packages.
Found 1 direct dependencies.
Root project is "github.com/icio/dep-ensure-hang-repro"
 1 transitively valid internal packages
 1 external packages imported from 1 projects
(0)   ✓ select (root)
(1)	? attempt bitbucket.org/zombiezen/gopdf with 1 pkgs; 6 versions to try
(1)	    try bitbucket.org/zombiezen/gopdf@default
(1)	✓ select bitbucket.org/zombiezen/gopdf@default w/1 pkgs
  ✓ found solution with 1 packages from 1 projects

Solver wall times by segment:
     b-source-exists: 1.335016635s
         b-list-pkgs: 1.182683639s
     b-list-versions: 384.111313ms
              b-gmal: 131.479728ms
            new-atom:     77.721µs
             satisfy:     64.579µs
         select-root:     52.466µs
         select-atom:     44.911µs
               other:      8.337µs
  b-deduce-proj-root:      2.125µs

  TOTAL: 3.033541454s

  Using default as constraint for direct dep bitbucket.org/zombiezen/gopdf
  Locking in default (1c63dc6) for direct dep bitbucket.org/zombiezen/gopdf
(1/1) Wrote bitbucket.org/zombiezen/gopdf@default

⚠️ Hangs:

$ rm -rf Gopkg.* vendor
$ mkdir bin; ln -s $(which git go dep) bin
$ tree .
.
├── bin
│   ├── dep -> /Users/icio/go/bin/dep
│   ├── git -> /usr/local/bin/git
│   └── go -> /usr/local/go/bin/go
└── main.go

$ PATH=$(realpath bin) dep init -v
Getting direct dependencies...
Checked 2 directories for packages.
Found 1 direct dependencies.
Root project is "github.com/icio/dep-ensure-hang-repro"
 1 transitively valid internal packages
 1 external packages imported from 1 projects
(0)   ✓ select (root)

    ... waits here indefinitely ...

^CSignal received: waiting for 1 ops to complete...
(1)	  ← no more versions of bitbucket.org/zombiezen/gopdf to try; begin backtrack
  ✗ solving failed

Solver wall times by segment:
     b-source-exists: 14.486804812s
               other:      73.474µs
         select-root:      43.564µs
            new-atom:       5.505µs
  b-deduce-proj-root:       2.323µs

  TOTAL: 14.486929678s

init failed: unable to solve the dependency graph: Solving failure: no valid source could be created:
	failed to set up sources from the following URLs:
https://bitbucket.org/zombiezen/gopdf
: hg is not installed:
	failed to set up sources from the following URLs:
ssh://hg@bitbucket.org/zombiezen/gopdf
: hg is not installed:
	failed to set up sources from the following URLs:
http://bitbucket.org/zombiezen/gopdf
: hg is not installed:
	failed to set up sources from the following URLs:
https://bitbucket.org/zombiezen/gopdf
: remote repository at https://bitbucket.org/zombiezen/gopdf does not exist, or is inaccessible: remote: Not Found
fatal: repository 'https://bitbucket.org/zombiezen/gopdf/' not found
: exit status 128
	failed to set up sources from the following URLs:
ssh://git@bitbucket.org/zombiezen/gopdf
: remote repository at ssh://git@bitbucket.org/zombiezen/gopdf does not exist, or is inaccessible: error: cannot run ssh: No such file or directory
fatal: unable to fork
: exit status 128
	failed to set up sources from the following URLs:
git://bitbucket.org/zombiezen/gopdf
: remote repository at git://bitbucket.org/zombiezen/gopdf does not exist, or is inaccessible: : signal: interrupt
	failed to set up sources from the following URLs:
http://bitbucket.org/zombiezen/gopdf
: context canceled

Not sure if relevant, but here's my git config:

$ git config --list | sort
alias.ignored=!git ls-files -v | grep ^[[:lower:]]
color.ui=auto
core.editor=vim
credential.helper=osxkeychain
diff.tool=Kaleidoscope
difftool.Kaleidoscope.cmd=ksdiff --partial-changeset --relative-path "$MERGED" -- "$LOCAL" "$REMOTE"
difftool.prompt=false
http.cookiefile=/Users/icio/.gitcookies
merge.tool=Kaleidoscope
mergetool.Kaleidoscope.cmd=ksdiff --merge --output "$MERGED" --base "$BASE" -- "$LOCAL" --snapshot "$REMOTE" --snapshot
mergetool.Kaleidoscope.trustexitcode=true
mergetool.prompt=false
pager.diff=diff-highlight | less
pager.log=diff-highlight | less
pager.show=diff-highlight | less
push.default=simple
ui.color=auto
url.git@github.com:.insteadof=https://github.com/
url.git@github.com:unravelin.insteadof=https://github.com/unravelin
user.email=paul...
user.name=Paul...

What did you expect to see?

dep init either error that hg was required but not installed; or succeed without it.

What did you see instead?

dep init hangs forever.

[icio]

Note that the same behaviour is exhibited when running dep ensure.

[icio]

Possibly related: #1622

[mvdan]

Dep was officially deprecated earlier this year, and the proposal to archive this repository was accepted. As such, I'm closing outstanding issues before archiving the repository. For any further comments, please use the proposal thread on the Go issue tracker. Thanks!