Auto-heal on corrupted lockfile with missing deps

Following up on rubygems#6355, which
turned a crash into a nicer error message, this commit auto-heals the
corrupt lockfile instead.

In this particular case (a corrupt Gemfile.lock with missing
dependencies) the LazySpecification will not have accurate dependency
information, we have to materialize the SpecSet to determine there are
missing dependencies. We've already got a way to handle this, via
`SpecSet#incomplete_specs`, but it wasn't quite working for this case
because we'd get to `@incomplete_specs += lookup[name]` and
`lookup[name]` would be empty for the dependency.

With this commit we catch it a bit earlier, marking the spec containing
the missing dependency as incomplete.

bundler/lib/bundler/installer/parallel_installer.rb

@@ -47,13 +47,6 @@ def dependencies_installed?(all_specs)
         dependencies.all? {|d| installed_specs.include? d.name }
       end
 
-      # Check whether spec's dependencies are missing, which can indicate a
-      # corrupted lockfile
-      def dependencies_missing?(all_specs)
-        spec_names = all_specs.map(&:name)
-        dependencies.any? {|d| !spec_names.include? d.name }
-      end
-
       # Represents only the non-development dependencies, the ones that are
       # itself and are in the total list.
       def dependencies
@@ -123,11 +116,7 @@ def check_for_unmet_dependencies
       unmet_dependencies.each do |spec, unmet_spec_dependencies|
         unmet_spec_dependencies.each do |unmet_spec_dependency|
           found = @specs.find {|s| s.name == unmet_spec_dependency.name && !unmet_spec_dependency.matches_spec?(s.spec) }
-          if found
-            warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name}, unsatisfied by #{found.full_name}"
-          else
-            warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name} but missing from lockfile"
-          end
+          warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name}, unsatisfied by #{found.full_name}"
         end
       end
 
@@ -224,8 +213,6 @@ def enqueue_specs
         if spec.dependencies_installed? @specs
           spec.state = :enqueued
           worker_pool.enq spec
-        elsif spec.dependencies_missing? @specs
-          spec.state = :failed
         end
       end
     end

bundler/lib/bundler/spec_set.rb

@@ -31,7 +31,7 @@ def for(dependencies, check = false, platforms = [nil])
         handled[key] = true
 
         specs_for_dep = specs_for_dependency(*dep)
-        if specs_for_dep.any?
+        if specs_for_dep.any? && dependencies_available?(specs_for_dep.first)
           specs.concat(specs_for_dep)
 
           specs_for_dep.first.dependencies.each do |d|
@@ -202,5 +202,9 @@ def tsort_each_child(s)
         lookup[d.name].each {|s2| yield s2 }
       end
     end
+
+    def dependencies_available?(spec)
+      spec.dependencies.all? {|d| d.type == :development || d.name == "bundler" || lookup[d.name].any? }
+    end
   end
 end

bundler/spec/lock/lockfile_spec.rb

@@ -1221,7 +1221,7 @@
       and include("Either installing with `--full-index` or running `bundle update rack_middleware` should fix the problem.")
   end
 
-  it "errors gracefully on a corrupt lockfile" do
+  it "auto-heals when the lockfile is missing dependent specs" do
     build_repo4 do
       build_gem "minitest-bisect", "1.6.0" do |s|
         s.add_dependency "path_expander", "~> 1.1"
@@ -1253,10 +1253,25 @@
     L
 
     cache_gems "minitest-bisect-1.6.0", "path_expander-1.1.1", :gem_repo => gem_repo4
-    bundle :install, :raise_on_error => false
+    bundle :install
 
-    expect(err).not_to include("ERROR REPORT TEMPLATE")
-    expect(err).to include("path_expander (~> 1.1), dependency of minitest-bisect-1.6.0 but missing from lockfile")
+    expect(lockfile).to eq <<~L
+      GEM
+        remote: #{file_uri_for(gem_repo4)}/
+        specs:
+          minitest-bisect (1.6.0)
+            path_expander (~> 1.1)
+          path_expander (1.1.1)
+
+      PLATFORMS
+        #{lockfile_platforms}
+
+      DEPENDENCIES
+        minitest-bisect
+
+      BUNDLED WITH
+         #{Bundler::VERSION}
+    L
   end
 
   it "auto-heals when the lockfile is missing specs" do