1 files changed, 21 insertions, 11 deletions

diff --git a/lib/rubygems/commands/exec_command.rb b/lib/rubygems/commands/exec_command.rb
index d588804290..1feafbdd35 100644
--- a/lib/rubygems/commands/exec_command.rb
+++ b/lib/rubygems/commands/exec_command.rb
@@ -57,8 +57,6 @@ to the same gem path as user-installed gems.
   end
 
   def execute
-    gem_paths = { "GEM_HOME" => Gem.paths.home, "GEM_PATH" => Gem.paths.path.join(File::PATH_SEPARATOR), "GEM_SPEC_CACHE" => Gem.paths.spec_cache_dir }.compact
-
     check_executable
 
     print_command
@@ -74,9 +72,6 @@ to the same gem path as user-installed gems.
     end
 
     load!
-  ensure
-    ENV.update(gem_paths) if gem_paths
-    Gem.clear_paths
   end
 
   private
@@ -143,7 +138,7 @@ to the same gem path as user-installed gems.
   end
 
   def set_gem_exec_install_paths
-    home = File.join(Gem.dir, "gem_exec")
+    home = Gem.dir
 
     ENV["GEM_PATH"] = ([home] + Gem.path).join(File::PATH_SEPARATOR)
     ENV["GEM_HOME"] = home
@@ -178,6 +173,9 @@ to the same gem path as user-installed gems.
   rescue Gem::InstallError => e
     alert_error "Error installing #{gem_name}:\n\t#{e.message}"
     terminate_interaction 1
+  rescue Gem::DependencyResolutionError => e
+    alert_error "Error installing #{gem_name}:\n\t#{e.message}"
+    terminate_interaction 2
   rescue Gem::GemNotFoundException => e
     show_lookup_failure e.name, e.version, e.errors, false
 
@@ -200,7 +198,7 @@ to the same gem path as user-installed gems.
     argv = ARGV.clone
     ARGV.replace options[:args]
 
-    exe = executable = options[:executable]
+    executable = options[:executable]
 
     contains_executable = Gem.loaded_specs.values.select do |spec|
       spec.executables.include?(executable)
@@ -211,13 +209,22 @@ to the same gem path as user-installed gems.
     end
 
     if contains_executable.empty?
-      if (spec = Gem.loaded_specs[executable]) && (exe = spec.executable)
-        contains_executable << spec
-      else
+      spec = Gem.loaded_specs[executable]
+
+      if spec.nil? || spec.executables.empty?
         alert_error "Failed to load executable `#{executable}`," \
               " are you sure the gem `#{options[:gem_name]}` contains it?"
         terminate_interaction 1
       end
+
+      if spec.executables.size > 1
+        alert_error "Ambiguous which executable from gem `#{executable}` should be run: " \
+              "the options are #{spec.executables.sort}, specify one via COMMAND, and use `-g` and `-v` to specify gem and version"
+        terminate_interaction 1
+      end
+
+      contains_executable << spec
+      executable = spec.executable
     end
 
     if contains_executable.size > 1
@@ -227,8 +234,11 @@ to the same gem path as user-installed gems.
       terminate_interaction 1
     end
 
-    load Gem.activate_bin_path(contains_executable.first.name, exe, ">= 0.a")
+    old_exe = $0
+    $0 = executable
+    load Gem.activate_bin_path(contains_executable.first.name, executable, ">= 0.a")
   ensure
+    $0 = old_exe if old_exe
     ARGV.replace argv
   end