Don't import execinfo.h when not necessary

Author: tnipen

.github/workflows/package.yml

@@ -65,7 +65,7 @@ jobs:
           # CIBW_SKIP: pp*-macosx* *i686* *musllinux* *p36* *p37* *p38* pp*
           CIBW_ARCHS_LINUX: auto aarch64
           CIBW_BUILD: cp310-musllinux_aarch64
-          CIBW_BUILD_VERBOSITY: 2
+          CIBW_BUILD_VERBOSITY: 1
           CIBW_BEFORE_ALL_LINUX: |
               # yum install -y lapack-devel armadillo-devel
               apk add armadillo-dev

src/api/util.cpp

@@ -5,12 +5,16 @@
 #include <cmath>
 #include <math.h>
 #include <assert.h>
-#include <execinfo.h>
 #include <signal.h>
 #include <iomanip>
 #include <cstdio>
 #include <exception>
 
+#ifdef DEBUG
+// This is not portable (only available on GNU/Linux
+#include <execinfo.h>
+#endif
+
 using namespace gridpp;
 
 bool gridpp::is_valid(float value) {