test: Emit a friendly error message if run with bash < 4.0.

The bash code in the test suite is using associative arrays which were
only added to bash as of release 4.0.

If the test suite is run with an older bash, we now immediately error
out and explain the situation, (instead of emitting confusing error
messages and failing dozens of tests, which is what happened before
this change).

1 files changed, 9 insertions, 1 deletions

diff --git a/test/notmuch-test b/test/notmuch-test
index 7feb5bdf..60c3ecbc 100755
--- a/test/notmuch-test
+++ b/test/notmuch-test
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Run tests
 #
@@ -6,6 +6,14 @@
 #
 # Adapted from a Makefile to a shell script by Carl Worth (2010)
 
+if [ ${BASH_VERSINFO[0]} -lt 4 ]; then
+    echo "Error: The notmuch test suite requires a bash version >= 4.0"
+    echo "due to use of associative arrays within the test suite."
+    echo "Please try again with a newer bash (or help us fix the"
+    echo "test suite to be more portable). Thanks."
+    exit 1
+fi
+
 cd $(dirname "$0")
 
 TESTS="basic new search json thread-naming reply dump-restore uuencode thread-order author-order from-guessing long-id encoding emacs"