From c22f3f5287384c7e4a2d45eb8de2cbfda23cb68e Mon Sep 17 00:00:00 2001
From: Kornel <kornel@geekhood.net>
Date: Sat, 28 Oct 2017 23:03:15 +0100
Subject: [PATCH] List available binary names

---
 src/cargo/ops/cargo_run.rs | 13 ++++++++-----
 tests/required-features.rs |  2 +-
 tests/run.rs               |  4 ++--
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/cargo/ops/cargo_run.rs b/src/cargo/ops/cargo_run.rs
index 3a4e7f6f2..636a62646 100644
--- a/src/cargo/ops/cargo_run.rs
+++ b/src/cargo/ops/cargo_run.rs
@@ -25,25 +25,28 @@ pub fn run(ws: &Workspace,
         }
     };
 
-    let mut bins = pkg.manifest().targets().iter().filter(|a| {
+    let bins: Vec<_> = pkg.manifest().targets().iter().filter(|a| {
         !a.is_lib() && !a.is_custom_build() && if !options.filter.is_specific() {
             a.is_bin()
         } else {
             options.filter.matches(a)
         }
-    });
-    if bins.next().is_none() {
+    })
+    .map(|bin| bin.name())
+    .collect();
+
+    if bins.len() == 0 {
         if !options.filter.is_specific() {
             bail!("a bin target must be available for `cargo run`")
         } else {
             // this will be verified in cargo_compile
         }
     }
-    if bins.next().is_some() {
+    if bins.len() > 1 {
         if !options.filter.is_specific() {
             bail!("`cargo run` requires that a project only have one \
                    executable; use the `--bin` option to specify which one \
-                   to run")
+                   to run ({})", bins.join(", "))
         } else {
             bail!("`cargo run` can run at most one executable, but \
                    multiple were specified")
diff --git a/tests/required-features.rs b/tests/required-features.rs
index 0f71d6d93..cdcc8d494 100644
--- a/tests/required-features.rs
+++ b/tests/required-features.rs
@@ -996,5 +996,5 @@ fn run_default_multiple_required_features() {
     assert_that(p.cargo("run"),
                 execs().with_status(101).with_stderr("\
 error: `cargo run` requires that a project only have one executable; \
-use the `--bin` option to specify which one to run"));
+use the `--bin` option to specify which one to run (foo1, foo2)"));
 }
diff --git a/tests/run.rs b/tests/run.rs
index 449c91caf..66e5350e4 100644
--- a/tests/run.rs
+++ b/tests/run.rs
@@ -256,7 +256,7 @@ fn too_many_bins() {
                 execs().with_status(101)
                        .with_stderr("[ERROR] `cargo run` requires that a project only \
                                      have one executable; use the `--bin` option \
-                                     to specify which one to run\n"));
+                                     to specify which one to run ([..])\n"));
 }
 
 #[test]
@@ -278,7 +278,7 @@ fn too_many_bins_implicit() {
                 execs().with_status(101)
                        .with_stderr("[ERROR] `cargo run` requires that a project only \
                                      have one executable; use the `--bin` option \
-                                     to specify which one to run\n"));
+                                     to specify which one to run ([..])\n"));
 }
 
 #[test]
-- 
2.30.2