From ffebf2c4979c51835dce409f22c6339996c3cd09 Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Mon, 28 Sep 2026 16:14:59 -0500
Subject: [PATCH] Add test cases for missing programs with os/spawn and
 os/execute.

---
 src/core/os.c       | 16 ++++++++--------
 test/suite-ev.janet | 13 +++++++++++++
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/src/core/os.c b/src/core/os.c
index afa6b886..b4de8456 100644
--- a/src/core/os.c
+++ b/src/core/os.c
@@ -1342,13 +1342,13 @@ static Janet os_execute_impl(int32_t argc, Janet *argv, JanetExecuteMode mode) {
     if (cp_failed)  {
         char msgbuf[256];
         msgbuf[0] = '\0';
-        FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
-                      NULL,
-                      cp_error_code,
-                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                      msgbuf,
-                      sizeof(msgbuf),
-                      NULL);
+        FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+                NULL,
+                cp_error_code,
+                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                msgbuf,
+                sizeof(msgbuf),
+                NULL);
         if (!*msgbuf) snprintf(msgbuf, sizeof(msgbuf), "%" PRIu32, (uint32_t) cp_error_code);
         char *c = msgbuf;
         while (*c) {
@@ -1358,7 +1358,7 @@ static Janet os_execute_impl(int32_t argc, Janet *argv, JanetExecuteMode mode) {
             }
             c++;
         }
-        janet_panicf("failed to create process: %s", janet_cstringv(msgbuf));
+        janet_panicf("failed to create process: %V", janet_cstringv(msgbuf));
     }
 
     pHandle = processInfo.hProcess;
diff --git a/test/suite-ev.janet b/test/suite-ev.janet
index d2ba2337..dd7de68a 100644
--- a/test/suite-ev.janet
+++ b/test/suite-ev.janet
@@ -641,4 +641,17 @@
     (string "'" x "'")))
 (assert (= 0 (os/shell (string/join [;run janet "-e" (shell-quote "(os/exit 0)")] " "))) "os/shell simple")
 
+# os/spawn and os/execute when program does not exist gives a normal error
+(def dne-path "this-long-binary-name-does-not-exist")
+(assert (nil? (os/stat dne-path :mode)) "binary path does not exist 1")
+(assert (let [[ok _result]
+              (protect
+                (let [process (os/spawn [dne-path] :p)]
+                  # if initial process launch works, it should at least fail with a non-zero exit code.
+                  (if-not (= 0 (:wait process))
+                    (error "should error"))))]
+          (not ok))
+        "binary path does not exist 2 - os/spawn")
+(assert (let [[ok _result] (protect (os/execute [dne-path] :px))] (not ok)) "binary path does not exist 2 - os/execute")
+
 (end-suite)