diff --git a/TODO b/TODO
index 048270bf51..383b45af54 100644
--- a/TODO
+++ b/TODO
@@ -41,9 +41,6 @@ Features:
   the entire system, with the exception of one specific service. See:
   https://lists.freedesktop.org/archives/systemd-devel/2018-February/040369.html
 
-* check what setting the login shell to /bin/false vs. /sbin/nologin means and
-  do the right thing in get_user_creds_clean() with it.
-
 * maybe rework get_user_creds() to query the user database if $SHELL is used
   for root, but only then.
 
diff --git a/src/test/test-user-util.c b/src/test/test-user-util.c
index 17a8520741..3a943bf10f 100644
--- a/src/test/test-user-util.c
+++ b/src/test/test-user-util.c
@@ -19,6 +19,7 @@
 ***/
 
 #include "alloc-util.h"
+#include "log.h"
 #include "macro.h"
 #include "string-util.h"
 #include "user-util.h"
@@ -28,14 +29,26 @@
 static void test_uid_to_name_one(uid_t uid, const char *name) {
         _cleanup_free_ char *t = NULL;
 
+        log_info("/* %s("UID_FMT", \"%s\") */", __func__, uid, name);
+
         assert_se(t = uid_to_name(uid));
+        if (!synthesize_nobody() && streq(name, NOBODY_USER_NAME)) {
+                log_info("(skipping detailed tests because nobody is not synthesized)");
+                return;
+        }
         assert_se(streq_ptr(t, name));
 }
 
 static void test_gid_to_name_one(gid_t gid, const char *name) {
         _cleanup_free_ char *t = NULL;
 
+        log_info("/* %s("GID_FMT", \"%s\") */", __func__, gid, name);
+
         assert_se(t = gid_to_name(gid));
+        if (!synthesize_nobody() && streq(name, NOBODY_GROUP_NAME)) {
+                log_info("(skipping detailed tests because nobody is not synthesized)");
+                return;
+        }
         assert_se(streq_ptr(t, name));
 }
 
@@ -43,6 +56,8 @@ static void test_parse_uid(void) {
         int r;
         uid_t uid;
 
+        log_info("/* %s */", __func__);
+
         r = parse_uid("100", &uid);
         assert_se(r == 0);
         assert_se(uid == 100);
@@ -55,6 +70,7 @@ static void test_parse_uid(void) {
 }
 
 static void test_uid_ptr(void) {
+        log_info("/* %s */", __func__);
 
         assert_se(UID_TO_PTR(0) != NULL);
         assert_se(UID_TO_PTR(1000) != NULL);
@@ -64,6 +80,8 @@ static void test_uid_ptr(void) {
 }
 
 static void test_valid_user_group_name(void) {
+        log_info("/* %s */", __func__);
+
         assert_se(!valid_user_group_name(NULL));
         assert_se(!valid_user_group_name(""));
         assert_se(!valid_user_group_name("1"));
@@ -90,6 +108,8 @@ static void test_valid_user_group_name(void) {
 }
 
 static void test_valid_user_group_name_or_id(void) {
+        log_info("/* %s */", __func__);
+
         assert_se(!valid_user_group_name_or_id(NULL));
         assert_se(!valid_user_group_name_or_id(""));
         assert_se(valid_user_group_name_or_id("0"));
@@ -119,6 +139,7 @@ static void test_valid_user_group_name_or_id(void) {
 }
 
 static void test_valid_gecos(void) {
+        log_info("/* %s */", __func__);
 
         assert_se(!valid_gecos(NULL));
         assert_se(valid_gecos(""));
@@ -129,6 +150,7 @@ static void test_valid_gecos(void) {
 }
 
 static void test_valid_home(void) {
+        log_info("/* %s */", __func__);
 
         assert_se(!valid_home(NULL));
         assert_se(!valid_home(""));
@@ -146,12 +168,23 @@ static void test_valid_home(void) {
 }
 
 static void test_get_user_creds_one(const char *id, const char *name, uid_t uid, gid_t gid, const char *home, const char *shell) {
-        const char *rhome;
-        const char *rshell;
-        uid_t ruid;
-        gid_t rgid;
+        const char *rhome = NULL;
+        const char *rshell = NULL;
+        uid_t ruid = UID_INVALID;
+        gid_t rgid = GID_INVALID;
+        int r;
 
-        assert_se(get_user_creds(&id, &ruid, &rgid, &rhome, &rshell) >= 0);
+        log_info("/* %s(\"%s\", \"%s\", "UID_FMT", "GID_FMT", \"%s\", \"%s\") */",
+                 __func__, id, name, uid, gid, home, shell);
+
+        r = get_user_creds(&id, &ruid, &rgid, &rhome, &rshell);
+        log_info_errno(r, "got \"%s\", "UID_FMT", "GID_FMT", \"%s\", \"%s\": %m",
+                       id, ruid, rgid, strnull(rhome), strnull(rshell));
+        if (!synthesize_nobody() && streq(name, NOBODY_USER_NAME)) {
+                log_info("(skipping detailed tests because nobody is not synthesized)");
+                return;
+        }
+        assert_se(r == 0);
         assert_se(streq_ptr(id, name));
         assert_se(ruid == uid);
         assert_se(rgid == gid);
@@ -160,15 +193,23 @@ static void test_get_user_creds_one(const char *id, const char *name, uid_t uid,
 }
 
 static void test_get_group_creds_one(const char *id, const char *name, gid_t gid) {
-        gid_t rgid;
+        gid_t rgid = GID_INVALID;
+        int r;
 
-        assert_se(get_group_creds(&id, &rgid) >= 0);
+        log_info("/* %s(\"%s\", \"%s\", "GID_FMT") */", __func__, id, name, gid);
+
+        r = get_group_creds(&id, &rgid);
+        log_info_errno(r, "got \"%s\", "GID_FMT": %m", id, rgid);
+        if (!synthesize_nobody() && streq(name, NOBODY_GROUP_NAME)) {
+                log_info("(skipping detailed tests because nobody is not synthesized)");
+                return;
+        }
+        assert_se(r == 0);
         assert_se(streq_ptr(id, name));
         assert_se(rgid == gid);
 }
 
 int main(int argc, char*argv[]) {
-
         test_uid_to_name_one(0, "root");
         test_uid_to_name_one(UID_NOBODY, NOBODY_USER_NAME);
         test_uid_to_name_one(0xFFFF, "65535");