This reference to __FILE__ would include the whole $srcdir - hence triggering the
> ==> WARNING: Package contains reference to $srcdir
and preventing reproducible builds.

diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index 2fb0d2c..f89e1c3 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -104,7 +104,7 @@
     do { \
         static SDL_bool seen = SDL_FALSE; \
         if (!seen) { \
-            fprintf(stderr, "FIXME: %s (%s, %s:%d)\n", x, __FUNCTION__, __FILE__, __LINE__); \
+            fprintf(stderr, "FIXME: %s (%s, SDL12_compat.c:%d)\n", x, __FUNCTION__, __LINE__); \
             seen = SDL_TRUE; \
         } \
     } while (0)