--- vdr-2.4.6.orig/config.h	2021-02-16 11:20:23.614000000 +0100
+++ vdr-2.4.6.orig/config.h	2021-02-16 11:40:25.313000000 +0100
@@ -19,6 +19,7 @@ 
 #include "i18n.h"
 #include "font.h"
 #include "tools.h"
+#include <limits.h>
 
 // VDR's own version number:
 
--- vdr-2.4.6.orig/i18n.h	2021-02-16 11:20:23.625000000 +0100
+++ vdr-2.4.6.orig/i18n.h	2021-02-16 11:26:25.920000000 +0100
@@ -46,7 +46,7 @@ 
    ///< have an actual locale installed. The rest are just dummy entries
    ///< to allow having three letter language codes for other languages
    ///< that have no actual locale on this system.
-const char *I18nTranslate(const char *s, const char *Plugin = NULL) __attribute_format_arg__(1);
+const char *I18nTranslate(const char *s, const char *Plugin = NULL)  __attribute__((__format_arg__ (1)));
    ///< Translates the given string (with optional Plugin context) into
    ///< the current language. If no translation is available, the original
    ///< string will be returned.
--- vdr-2.4.6.orig/osd.c	2021-02-16 11:20:23.627000000 +0100
+++ vdr-2.4.6.orig/osd.c	2021-02-16 11:27:10.554000000 +0100
@@ -12,7 +12,7 @@ 
 #include <stdlib.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
-#include <sys/unistd.h>
+#include <unistd.h>
 #include "device.h"
 #include "tools.h"
 
--- vdr-2.4.6.orig/thread.c	2021-02-16 11:20:23.602000000 +0100
+++ vdr-2.4.6.orig/thread.c	2021-02-16 11:29:49.318000000 +0100
@@ -160,7 +160,9 @@ 
   writeLockThreadId = 0;
   pthread_rwlockattr_t attr;
   pthread_rwlockattr_init(&attr);
+#if defined(__GLIBC__)
   pthread_rwlockattr_setkind_np(&attr, PreferWriter ? PTHREAD_RWLOCK_PREFER_WRITER_NP : PTHREAD_RWLOCK_PREFER_READER_NP);
+#endif
   pthread_rwlock_init(&rwlock, &attr);
 }
 
@@ -210,7 +212,7 @@ 
   locked = 0;
   pthread_mutexattr_t attr;
   pthread_mutexattr_init(&attr);
-  pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
+  pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
   pthread_mutex_init(&mutex, &attr);
 }
 
--- vdr-2.4.6.orig/tools.c	2021-02-16 11:20:23.617000000 +0100
+++ vdr-2.4.6.orig/tools.c	2021-02-16 11:40:52.178000000 +0100
@@ -27,6 +27,7 @@ 
 #include <utime.h>
 #include "i18n.h"
 #include "thread.h"
+#include <limits.h>
 
 int SysLogLevel = 3;
 
@@ -654,7 +655,7 @@ 
 {
   if (!FileName)
      return NULL;
-  char *TargetName = canonicalize_file_name(FileName);
+  char *TargetName = realpath(FileName, NULL);
   if (!TargetName) {
      if (errno == ENOENT) // file doesn't exist
         TargetName = strdup(FileName);
@@ -1544,7 +1545,7 @@ 
 struct dirent *cReadDir::Next(void)
 {
   if (directory) {
-#if !__GLIBC_PREREQ(2, 24) // readdir_r() is deprecated as of GLIBC 2.24
+#if __GLIBC__
      while (readdir_r(directory, &u.d, &result) == 0 && result) {
 #else
      while ((result = readdir(directory)) != NULL) {
--- vdr-2.4.6.orig/tools.h	2021-02-16 11:20:23.617000000 +0100
+++ vdr-2.4.6.orig/tools.h	2021-02-16 11:36:53.403000000 +0100
@@ -28,6 +28,16 @@ 
 #include <sys/types.h>
 #include "thread.h"
 
+#ifndef ACCESSPERMS
+# define ACCESSPERMS (S_IRWXU|S_IRWXG|S_IRWXO) /* 0777 */
+#endif
+#ifndef ALLPERMS
+# define ALLPERMS (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO)/* 07777 */
+#endif
+#ifndef DEFFILEMODE
+# define DEFFILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)/* 0666*/
+#endif
+
 typedef unsigned char uchar;
 
 extern int SysLogLevel;
@@ -412,7 +422,7 @@ 
 private:
   DIR *directory;
   struct dirent *result;
-#if !__GLIBC_PREREQ(2, 24) // readdir_r() is deprecated as of GLIBC 2.24
+#if __GLIBC__
   union { // according to "The GNU C Library Reference Manual"
     struct dirent d;
     char b[offsetof(struct dirent, d_name) + NAME_MAX + 1];
@@ -777,7 +787,7 @@ 
         data[i] = T(0);
     size = 0;
   }
-  void Sort(__compar_fn_t Compare)
+  void Sort(int (*Compare)(const void *, const void *))
   {
     qsort(data, size, sizeof(T), Compare);
   }
--- vdr-2.4.6.orig/vdr.c	2021-02-16 11:20:23.617000000 +0100
+++ vdr-2.4.6.orig/vdr.c	2021-02-16 11:38:27.790000000 +0100
@@ -689,12 +689,18 @@ 
         }
      }
   else if (Terminal) {
+#ifdef __GLIBC__
      // Claim new controlling terminal
      stdin  = freopen(Terminal, "r", stdin);
      stdout = freopen(Terminal, "w", stdout);
      stderr = freopen(Terminal, "w", stderr);
      HasStdin = true;
      tcgetattr(STDIN_FILENO, &savedTm);
+#else
+     // stdin, stdout, stderr are declared FILE const* by musl C library
+     fprintf(stderr, "Option '-t' is only supported if VDR has been built against glibc.\n");
+     return 2;
+#endif
      }
 
   isyslog("VDR version %s started", VDRVERSION);