Backported from upstream PR: https://github.com/urfave/cli/pull/1299
---
diff --git a/app_test.go b/app_test.go
index 33024ff..6b3aaa3 100644
--- a/app_test.go
+++ b/app_test.go
@@ -513,18 +513,18 @@ func TestApp_RunAsSubcommandParseFlags(t *testing.T) {
 func TestApp_RunAsSubCommandIncorrectUsage(t *testing.T) {
 	a := App{
 		Flags: []Flag{
-			StringFlag{Name: "--foo"},
+			StringFlag{Name: "foo"},
 		},
 		Writer: bytes.NewBufferString(""),
 	}
 
 	set := flag.NewFlagSet("", flag.ContinueOnError)
-	_ = set.Parse([]string{"", "---foo"})
+	_ = set.Parse([]string{"", "-bar"})
 	c := &Context{flagSet: set}
 
 	err := a.RunAsSubcommand(c)
 
-	expect(t, err, errors.New("bad flag syntax: ---foo"))
+	expect(t, err.Error(), "flag provided but not defined: -bar")
 }
 
 func TestApp_CommandWithFlagBeforeTerminator(t *testing.T) {
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<tr><td><span title='2021-01-28 20:48:55 +0200'>2021-01-28</span></td><td><a href='/guix/commit/gnu/packages/mono.scm?id=1649d0f20985551a92ba2182e4e2ad1fbc9ee160'>gnu: libgdiplus: Update to 6.0.5.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mono.scm (libgdiplus): Update to 6.0.5.

Signed-off-by: Efraim Flashner &lt;efraim@flashner.co.il&gt;
</span></span></td><td>Vincent Legoll</td></tr>

<tr><td><span title='2020-11-13 19:43:25 +0100'>2020-11-13</span></td><td><a href='/guix/commit/gnu/packages/julia.scm?id=f6e031ab36fd99ad3536caabfdaefcc2b5f606a1'>gnu: julia: Update to 1.5.3.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/julia.scm (julia): Update to 1.5.3.
(libuv-julia): Update to 1fcc6d66f9df74189c74d3d390f02202bb7db953.
(julia-patch): Update version.  No change to patches.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-11-13 19:43:25 +0100'>2020-11-13</span></td><td><a href='/guix/commit/gnu/packages/julia.scm?id=db2f95f1c24f5bfd05aa4c062cc6e7a32088345c'>gnu: libwhich: Compile natively, too.</a><span class='msg-avail'>...<span class='msg-tooltip'>This follows up on commit 12424b3ecfdf401c72804ddfa4b2fa2d8b1b68e5.

* gnu/packages/julia.scm (libwhich)[arguments]: Fix non-cross
compilation.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-11-13 15:02:32 +0100'>2020-11-13</span></td><td><a href='/guix/commit/gnu/packages/julia.scm?id=12424b3ecfdf401c72804ddfa4b2fa2d8b1b68e5'>gnu: libwhich: Cross-compile.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/julia.scm (libwhich)[arguments]: Use CC-FOR-TARGET.
Look for zlib in NATIVE-INPUTS.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>