build error on aarch64-linux-gnu: ncvalidator.c: error: ‘optind’ undeclared

[Alexander-Barth]

I am trying to cross-compile NetCDF 4.8.1 for the julia project but I have a compile error on aarch64-linux-gnu.

• the version of the software with which you are encountering an issue

NetCDF 4.8.1

• environmental information (i.e. Operating System, compiler info, java version, python version, etc.)

Cross-compilation: host: Linux x86_64 target: aarch64-linux-gnu
Compiler: aarch64-linux-gnu-gcc (GCC) 4.8.5

• a description of the issue with the steps needed to reproduce it

NetCDF is compiled and configured in the following way:

./configure --prefix=${prefix} \
    --build=${MACHTYPE} \
    --host=${target} \
    --enable-shared \
    --disable-static \
    --disable-dap-remote-tests \
    --disable-utilities

The full error message is:

ncvalidator.c: In function ‘main’:
ncvalidator.c:2288:5: warning: implicit declaration of function ‘getopt’ [-Wimplicit-function-declaration]
     while ((i = getopt(argc, argv, "xthq")) != EOF)
     ^
ncvalidator.c:2301:14: error: ‘optind’ undeclared (first use in this function)
     if (argv[optind] == NULL) { /* input file name is mandatory */
              ^
ncvalidator.c:2301:14: note: each undeclared identifier is reported only once for each function it appears in
make[3]: *** [Makefile:1322: ncvalidator.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: Leaving directory '/workspace/srcdir/netcdf-c-4.8.1/ncdump'
make[2]: *** [Makefile:1401: all-recursive] Error 1
make[2]: Leaving directory '/workspace/srcdir/netcdf-c-4.8.1/ncdump'
make[1]: *** [Makefile:729: all-recursive] Error 1
make[1]: Leaving directory '/workspace/srcdir/netcdf-c-4.8.1'
make: *** [Makefile:574: all] Error 2
Previous command exited with 2

The follow patch solves this issue:

From 86baf9cd28c20ad3589546639b44b776edef1684 Mon Sep 17 00:00:00 2001
From: Alexander Barth <barth.alexander@gmail.com>
Date: Wed, 2 Mar 2022 14:24:23 +0100
Subject: [PATCH 2/3] include getopt.h if available

---
 ncdump/ncvalidator.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ncdump/ncvalidator.c b/ncdump/ncvalidator.c
index dead0d03..8f275b10 100644
--- a/ncdump/ncvalidator.c
+++ b/ncdump/ncvalidator.c
@@ -60,6 +60,9 @@ THIS SOFTWARE.
 */
 
 #include "config.h"
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>  /* open() */
-- 
2.25.1

In essence we include getopt.h if HAVE_GETOPT_H is defined as in ncdump/ncdump.c

[DennisHeimbigner]

Fixed by PR #2316