refactor: err msgs 'cannot' > 'failed to'

in nearly all cases 'cannot' was used when an action was tried and
failed. 'failed to' is strictly better because:
* just because the action didn't work that time doesnt mean it
  cannot work
* it is better at drawing the users attention to a problem

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/ngit_push.rs b/tests/ngit_push.rs
index f37e027..d4b3894 100644
--- a/tests/ngit_push.rs
+++ b/tests/ngit_push.rs
@@ -58,7 +58,7 @@ mod when_proposal_isnt_associated_with_branch_name {
                 p.expect("fetching updates...\r\n")?;
                 p.expect_eventually("\r\n")?; // some updates listed here
                 p.expect_end_with(
-                    "Error: cannot find proposal that matches the current branch name\r\n",
+                    "Error: failed to find proposal that matches the current branch name\r\n",
                 )?;
                 for p in [51, 52, 53, 55, 56] {
                     relay::shutdown_relay(8000 + p)?;