Add Odin version mismatch warning to run-test and check-exercise (#150)

* Add Odin version mismatch warning to run-test and check-exercise

I added a file ODIN_VERSION at the top of the repo that contains
the version of the Odin compiler the test-runner is using.
This is used to warn contributors when the run run-test or
check-exercise before they push a PR that they are using a
different version (and that may cause compilation failure when
the exercise is checked by the track GHA).

I only made is a warning, this will not cause the checks to fail.

* Update regex for cygwin

On Cygwin when you execute `odin version`, it returns some path
in front of `odin version dev-...`, adjust the regex to remove
that part.

* Combine sed commands to clean up odin version

Author: rmonnet

ODIN_VERSION

@@ -0,0 +1 @@
+odin version dev-2025-10-nightly

bin/check-exercise.sh

@@ -144,4 +144,12 @@ check_format tests "${exercise_path}/${exercise_name}_test.odin"
 check_format example "${exercise_path}/.meta/example.odin"
 check_for_missing_test_descriptions "${exercise_path}/${exercise_name}_test.odin"
 
+    if [ -f ODIN_VERSION ]; then
+        local_version=$(odin version | sed -E 's/:.*$//; s/^.*odin version //')
+        supported_version=$(sed -E 's/^odin version //' ODIN_VERSION)
+        if [[ "$local_version" != "$supported_version" ]]; then
+            echo "⚠️[WARNING] Project's Odin version is: $supported_version but your local version is: $local_version"
+        fi
+    fi
+
 echo "Exercise $exercise_name pass all the checks!"

bin/run-test.sh

@@ -105,6 +105,14 @@ run_test() {
     else
         echo 'SUCCESS: The stub file failed the tests above as expected.'
     fi
+
+    if [ -f ODIN_VERSION ]; then
+        local_version=$(odin version | sed -E 's/:.*$//; s/^.*odin version //')
+        supported_version=$(sed -E 's/^odin version //' ODIN_VERSION)
+        if [[ "$local_version" != "$supported_version" ]]; then
+            echo "[WARNING] Project's Odin version is: $supported_version but your local version is: $local_version"
+        fi
+    fi
 }
 
 run_test "$@"