fix musl build

CMakeLists.txt

@@ -1057,9 +1057,15 @@ OPTION(ENABLE_BYTERANGE "Enable byte-range access to remote datasets.." OFF)
 # Check for the math library so it can be explicitly linked.
 IF(NOT WIN32)
   FIND_LIBRARY(HAVE_LIBM NAMES math m libm)
-  MESSAGE(STATUS "Found Math library: ${HAVE_LIBM}")
   IF(NOT HAVE_LIBM)
-    MESSAGE(FATAL_ERROR "Unable to find the math library.")
+    CHECK_FUNCTION_EXISTS(exp HAVE_LIBM_FUNC)
+    IF(NOT HAVE_LIBM_FUNC)
+        MESSAGE(FATAL_ERROR "Unable to find the math library.")
+    ELSE(NOT HAVE_LIBM_FUNC)
+        SET(HAVE_LIBM "")
+    ENDIF()
+  ELSE(NOT HAVE_LIBM)
+    MESSAGE(STATUS "Found Math library: ${HAVE_LIBM}")
   ENDIF()
 ENDIF()
 

config.h.cmake.in

@@ -441,6 +441,9 @@ with zip */
 /* if true, HDF5 is at least version 1.10.5 and supports UTF8 paths */
 #cmakedefine HDF5_UTF8_PATHS 1
 
+/* if true, backtrace support will be used. */
+#cmakedefine HAVE_EXECINFO_H 1
+
 /* if true, include JNA bug fix */
 #cmakedefine JNA 1
 

libhdf5/hdf5debug.c

@@ -5,7 +5,7 @@
 #include "config.h"
 #include <stdarg.h>
 #include <stdio.h>
-#if !defined _WIN32 && !defined __CYGWIN__
+#ifdef HAVE_EXECINFO_H
 #include <execinfo.h>
 #endif
 
@@ -15,15 +15,18 @@
 
 #define STSIZE 1000
 
+#ifdef HAVE_EXECINFO_H
 #ifdef H5BACKTRACE
 #  if !defined _WIN32 && !defined __CYGWIN__
 static void* stacktrace[STSIZE];
 #  endif
 #endif
+#endif
 
 int
 nch5breakpoint(int err)
 {
+#ifdef HAVE_EXECINFO_H
 #ifdef H5BACKTRACE
 #  if !defined _WIN32 && !defined __CYGWIN__
     int count = 0;
@@ -39,6 +42,7 @@ nch5breakpoint(int err)
     if(trace != NULL) free(trace);
 #    endif
 #  endif
+#endif
 #endif
     return err;
 }