fixup

Author: gnzlbg

libc-test/build.rs

@@ -1995,6 +1995,10 @@ fn test_linux(target: &str) {
         ),
     }
 
+    let arm = target.contains("arm");
+    let x86_64 = target.contains("x86_64");
+    let x86_32 = target.contains("i686");
+    let x32 = target.contains("x32");
     let mips = target.contains("mips");
     let mips32 = mips && !target.contains("64");
 
@@ -2097,23 +2101,26 @@ fn test_linux(target: &str) {
 
     // `sys/io.h` is only available on x86*, Alpha, IA64, and 32-bit ARM:
     // https://bugzilla.redhat.com/show_bug.cgi?id=1116162
-    if target.contains("x86")
-        || target.contains("i686")
-        || target.contains("arm")
-    {
+    if x86_64 || x86_32 || arm {
         headers! { cfg: "sys/io.h" }
     }
 
     // `sys/reg.h` is only available on x86 and x86_64
-    if target.contains("x86") || target.contains("i686") {
+    if x86_64 || x86_32 {
         headers! { cfg: "sys/reg.h" }
     }
 
     // sysctl system call is unsupported in x32 kernel:
-    if !target.contains("x32") {
+    if !x86_64_32 {
         headers! { cfg:  "sys/sysctl.h"}
     }
 
+    // <execinfo.h> is not supported by musl:
+    // https://www.openwall.com/lists/musl/2015/04/09/3
+    if !musl {
+        headers! { cfg: "execinfo.h" }
+    }
+
     // Include linux headers at the end:
     headers! {
         cfg: