Fix alpha legacy dir detection, Fix SemVer value ctor

xs/src/semver/semver.c

@@ -620,7 +620,7 @@ semver_numeric (semver_t *x) {
   return num;
 }
 
-static char *semver_strdup(const char *src) {
+char *semver_strdup(const char *src) {
   if (src == NULL) return NULL;
   size_t len = strlen(src) + 1;
   char *res = malloc(len);

xs/src/semver/semver.h

@@ -98,6 +98,9 @@ semver_is_valid (const char *s);
 int
 semver_clean (char *s);
 
+char *
+semver_strdup(const char *src);
+
 semver_t
 semver_copy(const semver_t *ver);