fix: too brittle invalid regex tests under bash 5.3 The exact error details depend on the system

diff --git a/test/assert_line.bats b/test/assert_line.bats
index 5a2f494..d42df0d 100755
--- a/test/assert_line.bats
+++ b/test/assert_line.bats

@@ -337,10 +337,17 @@
   run assert_line --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    cat <<ERR_MSG
 
 -- ERROR: assert_line --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
+--
+ERR_MSG
+    assert_test_fail <<ERR_MSG
+
+-- ERROR: assert_line --
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/assert_output.bats b/test/assert_output.bats
index 199f996..5341167 100755
--- a/test/assert_output.bats
+++ b/test/assert_output.bats

@@ -255,10 +255,11 @@
   run assert_output --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: assert_output --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/assert_regex.bats b/test/assert_regex.bats
index 4b8301a..42caad9 100644
--- a/test/assert_regex.bats
+++ b/test/assert_regex.bats

@@ -74,10 +74,11 @@
   run assert_regex value '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: assert_regex --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else 

diff --git a/test/assert_stderr.bats b/test/assert_stderr.bats
index cf8c1bc..e56b59d 100755
--- a/test/assert_stderr.bats
+++ b/test/assert_stderr.bats

@@ -268,10 +268,11 @@
   run assert_stderr --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: assert_stderr --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/assert_stderr_line.bats b/test/assert_stderr_line.bats
index f7d1ab7..a8b1141 100755
--- a/test/assert_stderr_line.bats
+++ b/test/assert_stderr_line.bats

@@ -350,10 +350,11 @@
   run assert_stderr_line --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: assert_stderr_line --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/refute_line.bats b/test/refute_line.bats
index f2a3925..81d0e6f 100755
--- a/test/refute_line.bats
+++ b/test/refute_line.bats

@@ -330,10 +330,11 @@
   run refute_line --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: refute_line --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/refute_output.bats b/test/refute_output.bats
index b0d3c4f..fb68875 100755
--- a/test/refute_output.bats
+++ b/test/refute_output.bats

@@ -199,10 +199,11 @@
 @test 'refute_output() --regexp <regexp>: returns 1 and displays an error message if <regexp> is not a valid extended regular expression' {
   run refute_output --regexp '[.*'
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: refute_output --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/refute_regex.bats b/test/refute_regex.bats
index eb56b18..a4ada12 100644
--- a/test/refute_regex.bats
+++ b/test/refute_regex.bats

@@ -90,10 +90,11 @@
   run refute_regex value '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: refute_regex --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/refute_stderr.bats b/test/refute_stderr.bats
index b1e8c8c..f4a79b6 100755
--- a/test/refute_stderr.bats
+++ b/test/refute_stderr.bats

@@ -212,10 +212,11 @@
   run refute_stderr --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<'ERR_MSG'
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: refute_stderr --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else

diff --git a/test/refute_stderr_line.bats b/test/refute_stderr_line.bats
index 67dcde1..5db4363 100755
--- a/test/refute_stderr_line.bats
+++ b/test/refute_stderr_line.bats

@@ -342,10 +342,11 @@
   run refute_stderr_line --regexp '[.*'
 
   if (( BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >=3) )); then
-    assert_test_fail <<"ERR_MSG"
+    [[ "$output" =~ "invalid regular expression "([^$'\n']+) ]]
+    assert_test_fail <<ERR_MSG
 
 -- ERROR: refute_stderr_line --
-invalid regular expression `[.*': Missing ']'
+invalid regular expression ${BASH_REMATCH[1]}
 --
 ERR_MSG
   else