diff -rupN a/options.c b/options.c

--- a/options.c	2019-06-28 17:15:31.515626363 -0400

+++ b/options.c	2019-06-28 17:18:59.490632337 -0400

@@ -440,7 +440,8 @@ parse_int(const char *optarg, char opt,

 }

 int

-parse_colon_separated_list(const char *paths, struct vect *vec)

+parse_colon_separated_list(const char *paths, struct vect *vec,

+			   enum opt_F_origin origin)

 {

 	/* PATHS contains a colon-separated list of directories and

 	 * files to load.  It's modeled after shell PATH variable,

@@ -467,6 +468,7 @@ parse_colon_separated_list(const char *p

 		struct opt_F_t arg = {

 			.pathname = tok,

 			.own_pathname = tok == clone,

+			.origin = origin,

 		};

 		if (VECT_PUSHBACK(vec, &arg) < 0)

 			/* Presumably this is not a deal-breaker.  */

@@ -494,16 +496,18 @@ opt_F_get_kind(struct opt_F_t *entry)

 	if (entry->kind == OPT_F_UNKNOWN) {

 		struct stat st;

 		if (lstat(entry->pathname, &st) < 0) {

-			fprintf(stderr, "Couldn't stat %s: %s\n",

-				entry->pathname, strerror(errno));

+			if (entry->origin == OPT_F_CMDLINE)

+				fprintf(stderr, "Couldn't stat %s: %s\n",

+					entry->pathname, strerror(errno));

 			entry->kind = OPT_F_BROKEN;

 		} else if (S_ISDIR(st.st_mode)) {

 			entry->kind = OPT_F_DIR;

 		} else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {

 			entry->kind = OPT_F_FILE;

 		} else {

-			fprintf(stderr, "%s is neither a regular file, "

-				"nor a directory.\n", entry->pathname);

+			if (entry->origin == OPT_F_CMDLINE)

+				fprintf(stderr, "%s is neither a regular file, "

+					"nor a directory.\n", entry->pathname);

 			entry->kind = OPT_F_BROKEN;

 		}

 	}

@@ -607,7 +611,8 @@ process_options(int argc, char **argv)

 			options.follow = 1;

 			break;

 		case 'F':

-			parse_colon_separated_list(optarg, &opt_F);

+			parse_colon_separated_list(optarg, &opt_F,

+						   OPT_F_CMDLINE);

 			break;

 		case 'h':

 			usage();

diff -rupN a/options.h b/options.h

--- a/options.h	2019-06-28 17:15:31.515626363 -0400

+++ b/options.h	2019-06-28 17:18:55.984632238 -0400

@@ -1,6 +1,6 @@

 /*

  * This file is part of ltrace.

- * Copyright (C) 2012,2013 Petr Machata, Red Hat Inc.

+ * Copyright (C) 2012, 2013, 2015 Petr Machata, Red Hat Inc.

  * Copyright (C) 2009,2010 Joe Damato

  * Copyright (C) 1998,2002,2008 Juan Cespedes

  * Copyright (C) 2006 Ian Wienand

@@ -77,10 +77,16 @@ enum opt_F_kind {

 	OPT_F_DIR,

 };

+enum opt_F_origin {

+	OPT_F_CMDLINE = 0,

+	OPT_F_ENVIRON,

+};

+

 struct opt_F_t {

 	char *pathname;

 	int own_pathname : 1;

 	enum opt_F_kind kind : 2;

+	enum opt_F_origin origin : 1;

 };

 /* If entry->kind is OPT_F_UNKNOWN, figure out whether it should be

@@ -98,7 +104,8 @@ void opt_F_destroy(struct opt_F_t *entry

  * The list is split and added to VEC, which shall be a vector

  * initialized like VECT_INIT(VEC, struct opt_F_t); Returns 0 on

  * success or a negative value on failure.  */

-int parse_colon_separated_list(const char *paths, struct vect *vec);

+int parse_colon_separated_list(const char *paths, struct vect *vec,

+			       enum opt_F_origin origin);

 /* Vector of struct opt_F_t.  */

 extern struct vect opt_F;

diff -rupN a/sysdeps/linux-gnu/hooks.c b/sysdeps/linux-gnu/hooks.c

--- a/sysdeps/linux-gnu/hooks.c	2013-11-04 20:08:03.000000000 -0500

+++ b/sysdeps/linux-gnu/hooks.c	2019-06-28 17:18:55.989632238 -0400

@@ -1,6 +1,6 @@

 /*

  * This file is part of ltrace.

- * Copyright (C) 2012, 2013 Petr Machata

+ * Copyright (C) 2012, 2013, 2015 Petr Machata

  *

  * This program is free software; you can redistribute it and/or

  * modify it under the terms of the GNU General Public License as

@@ -153,7 +153,7 @@ again:

 	if (xdg_sys != NULL) {

 		struct vect v;

 		VECT_INIT(&v, struct opt_F_t);

-		if (parse_colon_separated_list(xdg_sys, &v) < 0

+		if (parse_colon_separated_list(xdg_sys, &v, OPT_F_ENVIRON) < 0

 		    || VECT_EACH(&v, struct opt_F_t, NULL,

 				 add_dir_component_cb, &dirs) != NULL)

 			fprintf(stderr,

diff -rupN a/testsuite/ltrace.main/XDG_CONFIG_DIRS.exp b/testsuite/ltrace.main/XDG_CONFIG_DIRS.exp

--- a/testsuite/ltrace.main/XDG_CONFIG_DIRS.exp	1969-12-31 19:00:00.000000000 -0500

+++ b/testsuite/ltrace.main/XDG_CONFIG_DIRS.exp	2019-06-28 17:18:55.989632238 -0400

@@ -0,0 +1,35 @@

+# This file is part of ltrace.

+# Copyright (C) 2015 Petr Machata, Red Hat Inc.

+#

+# This program is free software; you can redistribute it and/or

+# modify it under the terms of the GNU General Public License as

+# published by the Free Software Foundation; either version 2 of the

+# License, or (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful, but

+# WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+# General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program; if not, write to the Free Software

+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

+# 02110-1301 USA

+

+set bin [ltraceCompile {} [ltraceSource c {

+    int main() { return 0; }

+}]]

+

+setenv XDG_CONFIG_DIRS "blah"

+ltraceRun -L -- $bin

+unsetenv XDG_CONFIG_DIRS

+

+if {[catch "exec $LTRACE -L -F blah -- $bin" output]} {

+    ltraceMatch [ltraceSource ltrace "$output"] {

+	{blah == 1}

+    }

+} else {

+    fail "expected error message regarding `blah`"

+}

+

+ltraceDone