Musl does not have sys/perm.h. Luckily, sys/io.h has the required
definitions both for musl and glibc.

diff -ruN xosview-1.23.orig/linux/serialmeter.cc xosview-1.23/linux/serialmeter.cc
--- xosview-1.23.orig/linux/serialmeter.cc	2020-07-11 14:10:34.000000000 +0200
+++ xosview-1.23/linux/serialmeter.cc	2023-05-05 22:13:19.863489393 +0200
@@ -25,7 +25,6 @@
  */
 #if defined(__i386__) || defined(__ia64__) || defined(__amd64__)
 #include <sys/io.h>
-#include <sys/perm.h>
 #define HAVE_IOPERM
 #endif