swtpm: fix build on darwin

pkgs/tools/security/swtpm/default.nix

@@ -28,23 +28,28 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [
     pkg-config unixtools.netstat expect socat
     perl # for pod2man
+    python3
     autoreconfHook
   ];
 
   checkInputs = [
-    python3 which
+    which
   ];
 
   buildInputs = [
     libtpms
-    openssl libtasn1 libseccomp
-    fuse glib json-glib
+    openssl libtasn1
+    glib json-glib
     gnutls
+  ] ++ lib.optionals stdenv.isLinux [
+    fuse
+    libseccomp
   ];
 
   configureFlags = [
-    "--with-cuse"
     "--localstatedir=/var"
+  ] ++ lib.optionals stdenv.isLinux [
+    "--with-cuse"
   ];
 
   postPatch = ''
@@ -56,9 +61,31 @@ stdenv.mkDerivation rec {
 
     # Use the correct path to the certtool binary
     # instead of relying on it being in the environment
-    substituteInPlace src/swtpm_localca/swtpm_localca.c --replace \
+    substituteInPlace src/swtpm_localca/swtpm_localca.c \
+      --replace \
+        '# define CERTTOOL_NAME "gnutls-certtool"' \
+        '# define CERTTOOL_NAME "${gnutls}/bin/certtool"' \
+      --replace \
         '# define CERTTOOL_NAME "certtool"' \
         '# define CERTTOOL_NAME "${gnutls}/bin/certtool"'
+
+    substituteInPlace tests/common --replace \
+        'CERTTOOL=gnutls-certtool;;' \
+        'CERTTOOL=certtool;;'
+
+    # Fix error on macOS:
+    # stat: invalid option -- '%'
+    # This is caused by the stat program not being the BSD version,
+    # as is expected by the test
+    substituteInPlace tests/common --replace \
+        'if [[ "$(uname -s)" =~ (Linux|CYGWIN_NT-) ]]; then' \
+        'if [[ "$(uname -s)" =~ (Linux|Darwin|CYGWIN_NT-) ]]; then'
+
+    # Otherwise certtool seems to pick up the system language on macOS,
+    # which might cause a test to fail
+    substituteInPlace tests/test_swtpm_setup_create_cert --replace \
+        '$CERTTOOL' \
+        'LC_ALL=C.UTF-8 $CERTTOOL'
   '';
 
   doCheck = true;