diff --git a/lang/ninja/src/build.sld b/lang/ninja/src/build.sld
index d1298f9..90496ad 100644
--- a/lang/ninja/src/build.sld
+++ b/lang/ninja/src/build.sld
@@ -55,9 +55,8 @@
           ; This file is produced by another build edge. Add it to our input vfs.
           (let ((prev-copy-input-files copy-input-files))
             (set! copy-input-files #~,(string-append #$prev-copy-input-files "\n" "$COREUTILS/mkdir -p bdir/" relative-to-root "/$($COREUTILS/dirname " path "); $COREUTILS/cp -rf " #$(force input-file) " bdir/" relative-to-root "/" path))); (set! vfs (vfs-append-file vfs (normalize-path path) (force input-file)))
-          (if (string-prefix? "/nix/store" path)
-              (fprintf (current-error-port) "Path doesn't exist as build edge: ~S\n" path)
-              (error "Path doesn't exist as build edge" path))))
+          (unless (string-prefix? "/nix/store" path)
+            (error "Path doesn't exist as build edge" path))))
 
       ; Workaround for Meson not adding the .so as build dependency when linking, instead using a .symbols file.
       ; This makes sense, as it only relinks when symbols change, but it breaks the dependency link, and is the only