diff -uNr postgresql-13.1/src/backend/commands/collationcmds.c postgresql-13.1.mod/src/backend/commands/collationcmds.c
--- postgresql-13.1/src/backend/commands/collationcmds.c	2020-11-10 00:24:30.000000000 +0200
+++ postgresql-13.1.mod/src/backend/commands/collationcmds.c	2021-02-09 15:40:24.275785513 +0200
@@ -381,7 +380,7 @@
 
 
 /* will we use "locale -a" in pg_import_system_collations? */
-#if defined(HAVE_LOCALE_T) && !defined(WIN32)
+#if defined(HAVE_LOCALE_T) && !defined(WIN32) && !defined(__ANDROID__)
 #define READ_LOCALE_A_OUTPUT
 #endif
 
@@ -464,7 +463,7 @@
 	UErrorCode	status;
 
 	status = U_ZERO_ERROR;
-	uloc_toLanguageTag(localename, buf, sizeof(buf), TRUE, &status);
+	uloc_toLanguageTag(localename, buf, sizeof(buf), true, &status);
 	if (U_FAILURE(status))
 		ereport(ERROR,
 				(errmsg("could not convert locale name \"%s\" to language tag: %s",