diff -urN a/src/basic/mountpoint-util.c b/src/basic/mountpoint-util.c
--- a/src/basic/mountpoint-util.c	2025-11-18 01:14:12.000000000 -0600
+++ b/src/basic/mountpoint-util.c	2026-03-29 15:01:10.720866440 -0500
@@ -127,7 +127,7 @@
         if (r < 0)
                 return r;
 
-        p = find_line_startswith(fdinfo, "mnt_id:");
+        p = (char*) find_line_startswith(fdinfo, "mnt_id:");
         if (!p) /* The mnt_id field is a relatively new addition */
                 return -EOPNOTSUPP;
 
@@ -554,7 +554,7 @@
 int dev_is_devtmpfs(void) {
         _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
         int mount_id, r;
-        char *e;
+        const char *e;
 
         r = path_get_mnt_id("/dev", &mount_id);
         if (r < 0)
diff -urN a/src/basic/process-util.c b/src/basic/process-util.c
--- a/src/basic/process-util.c	2025-11-18 01:14:12.000000000 -0600
+++ b/src/basic/process-util.c	2026-03-29 15:01:10.721866471 -0500
@@ -1793,7 +1793,7 @@
         if (r < 0)
                 return r;
 
-        p = find_line_startswith(fdinfo, "Pid:");
+        p = (char*) find_line_startswith(fdinfo, "Pid:");
         if (!p)
                 return -ENOTTY; /* not a pidfd? */
 
diff -urN a/src/basic/string-util.c b/src/basic/string-util.c
--- a/src/basic/string-util.c	2025-11-18 01:14:12.000000000 -0600
+++ b/src/basic/string-util.c	2026-03-29 15:01:10.720866440 -0500
@@ -1409,8 +1409,8 @@
         return strndup(a, strcspn(a, reject));
 }
 
-char *find_line_startswith(const char *haystack, const char *needle) {
-        char *p;
+const char *find_line_startswith(const char *haystack, const char *needle) {
+        const char *p;
 
         assert(haystack);
         assert(needle);
diff -urN a/src/basic/string-util.h b/src/basic/string-util.h
--- a/src/basic/string-util.h	2025-11-18 01:14:12.000000000 -0600
+++ b/src/basic/string-util.h	2026-03-29 15:01:10.720866440 -0500
@@ -26,14 +26,14 @@
 #define URI_UNRESERVED      ALPHANUMERICAL "-._~"       /* [RFC3986] */
 #define URI_VALID           URI_RESERVED URI_UNRESERVED /* [RFC3986] */
 
-static inline char* strstr_ptr(const char *haystack, const char *needle) {
+static inline const char* strstr_ptr(const char *haystack, const char *needle) {
         if (!haystack || !needle)
                 return NULL;
         return strstr(haystack, needle);
 }
 
-static inline char *strstrafter(const char *haystack, const char *needle) {
-        char *p;
+static inline const char *strstrafter(const char *haystack, const char *needle) {
+        const char *p;
 
         /* Returns NULL if not found, or pointer to first character after needle if found */
 
@@ -308,7 +308,7 @@
 #endif // 0
 char *strdupcspn(const char *a, const char *reject);
 
-char *find_line_startswith(const char *haystack, const char *needle);
+const char *find_line_startswith(const char *haystack, const char *needle);
 
 char *startswith_strv(const char *string, char **strv);
 
diff -urN a/src/libelogind/sd-bus/sd-bus.c b/src/libelogind/sd-bus/sd-bus.c
--- a/src/libelogind/sd-bus/sd-bus.c	2025-11-18 01:14:12.000000000 -0600
+++ b/src/libelogind/sd-bus/sd-bus.c	2026-03-29 14:55:42.302578511 -0500
@@ -1407,7 +1407,8 @@
 
 int bus_set_address_system_remote(sd_bus *b, const char *host) {
         _cleanup_free_ char *e = NULL;
-        char *m = NULL, *c = NULL, *a, *rbracket = NULL, *p = NULL;
+        const char *m = NULL, *at = NULL, *rbracket = NULL, *p = NULL;
+        char *a = NULL, *c = NULL;
 
         assert(b);
         assert(host);
@@ -1423,29 +1424,29 @@
                 e = bus_address_escape(t);
                 if (!e)
                         return -ENOMEM;
-        } else if ((a = strchr(host, '@'))) {
-                if (*(a + 1) == '[') {
+        } else if ((at = strchr(host, '@'))) {
+                if (*(at + 1) == '[') {
                         _cleanup_free_ char *t = NULL;
 
-                        rbracket = strchr(a + 1, ']');
+                        rbracket = strchr(at + 1, ']');
                         if (!rbracket)
                                 return -EINVAL;
                         t = new0(char, strlen(host));
                         if (!t)
                                 return -ENOMEM;
-                        strncat(t, host, a - host + 1);
-                        strncat(t, a + 2, rbracket - a - 2);
+                        strncat(t, host, at - host + 1);
+                        strncat(t, at + 2, rbracket - at - 2);
                         e = bus_address_escape(t);
                         if (!e)
                                 return -ENOMEM;
-                } else if (*(a + 1) == '\0' || strchr(a + 1, '@'))
+                } else if (*(at + 1) == '\0' || strchr(at + 1, '@'))
                         return -EINVAL;
         }
 
         /* Let's see if a port was given */
         m = strchr(rbracket ? rbracket + 1 : host, ':');
         if (m) {
-                char *t;
+                const char *t;
                 bool got_forward_slash = false;
 
                 p = m + 1;
diff -urN a/src/test/test-id128.c b/src/test/test-id128.c
--- a/src/test/test-id128.c	2025-11-18 01:14:12.000000000 -0600
+++ b/src/test/test-id128.c	2026-03-29 15:05:01.649650821 -0500
@@ -22,6 +22,18 @@
 #define UUID_WALDI "01020304-0506-0708-090a-0b0c0d0e0f10"
 #define STR_NULL "00000000000000000000000000000000"
 
+static bool id128_in_0(sd_id128_t id) {
+        return false;
+}
+
+static bool id128_in_1(sd_id128_t id, sd_id128_t a) {
+        return sd_id128_equal(id, a);
+}
+
+static bool id128_in_2(sd_id128_t id, sd_id128_t a, sd_id128_t b) {
+        return sd_id128_equal(id, a) || sd_id128_equal(id, b);
+}
+
 TEST(id128) {
         sd_id128_t id, id2;
         char t[SD_ID128_STRING_MAX], q[SD_ID128_UUID_STRING_MAX];
@@ -33,13 +45,14 @@
 
         assert_se(sd_id128_from_string(t, &id2) == 0);
         assert_se(sd_id128_equal(id, id2));
-        assert_se(sd_id128_in_set(id, id));
-        assert_se(sd_id128_in_set(id, id2));
-        assert_se(sd_id128_in_set(id, id2, id));
-        assert_se(sd_id128_in_set(id, ID128_WALDI, id));
-        assert_se(!sd_id128_in_set(id));
-        assert_se(!sd_id128_in_set(id, ID128_WALDI));
-        assert_se(!sd_id128_in_set(id, ID128_WALDI, ID128_WALDI));
+        /* Work around a Clang 22 frontend crash on sd_id128_in_set() with union varargs in this test. */
+        assert_se(id128_in_1(id, id));
+        assert_se(id128_in_1(id, id2));
+        assert_se(id128_in_2(id, id2, id));
+        assert_se(id128_in_2(id, ID128_WALDI, id));
+        assert_se(!id128_in_0(id));
+        assert_se(!id128_in_1(id, ID128_WALDI));
+        assert_se(!id128_in_2(id, ID128_WALDI, ID128_WALDI));
 
         if (sd_booted() > 0 && sd_id128_get_machine(NULL) >= 0) {
                 assert_se(sd_id128_get_machine(&id) == 0);