From 869c8e910a38532e49083acdf145c3bb98842568 Mon Sep 17 00:00:00 2001
From: Lukasz Stafiniak <lukstafi@gmail.com>
Date: Fri, 9 Aug 2024 12:22:17 +0200
Subject: [PATCH] Fix consistency check when env variable is not set

---
 CHANGELOG.md     |  1 +
 ppx_minidebug.ml | 31 ++++++++++++++++++-------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eab846f..1e78b11 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### Fixed
 
 - Write the log tree on the error "lexical scope of close_log not matching its dynamic scope", so the entries from the error message can be looked up.
+- Uncaught exception in the `[%%global_debug_log_level_from_env_var "..."]` consistency check when the environment variable is not defined.
 
 ## [1.6.0] -- 2024-08-08
 
diff --git a/ppx_minidebug.ml b/ppx_minidebug.ml
index 4dea7ba..935c4f1 100644
--- a/ppx_minidebug.ml
+++ b/ppx_minidebug.ml
@@ -1535,19 +1535,24 @@ let global_log_level_from_env_var ~check_consistency =
                 in
                 A.pstr_eval ~loc
                   [%expr
-                    let runtime_log_level =
-                      Stdlib.String.lowercase_ascii
-                      @@ Stdlib.Sys.getenv
-                           [%e
-                             Ast_helper.Exp.constant ~loc:s_loc
-                             @@ Ast_helper.Const.string ~loc:s_loc env_n]
-                    in
-                    if not (Stdlib.String.equal [%e lifted_log_level] runtime_log_level)
-                    then
-                      failwith
-                        ("ppx_minidebug: compile-time vs. runtime log level mismatch, \
-                          found '" ^ [%e lifted_log_level] ^ "' at compile time, '"
-                       ^ runtime_log_level ^ "' at runtime")]
+                    try
+                      let runtime_log_level =
+                        Stdlib.String.lowercase_ascii
+                        @@ Stdlib.Sys.getenv
+                             [%e
+                               Ast_helper.Exp.constant ~loc:s_loc
+                               @@ Ast_helper.Const.string ~loc:s_loc env_n]
+                      in
+                      if
+                        (not (Stdlib.String.equal "" runtime_log_level))
+                        && not
+                             (Stdlib.String.equal [%e lifted_log_level] runtime_log_level)
+                      then
+                        failwith
+                          ("ppx_minidebug: compile-time vs. runtime log level mismatch, \
+                            found '" ^ [%e lifted_log_level] ^ "' at compile time, '"
+                         ^ runtime_log_level ^ "' at runtime")
+                    with Stdlib.Not_found -> ()]
                   attrs
               else noop
             in