Re: Host requirements to build the Tools binaries

[RVP <rvp%SDF.ORG@localhost>]

> So this boils down to:  What APIs / standards does NetBSD (while
> building `tools`) expect to be implemented?

strptime is marked as XSI[1], so you'll need to add `_XOPEN_SOURCE' as the
man-page on Linux indicates (either on the cmd. line, or before any headers
are included, or in the very first header read as tsutsui@ said):

[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html

```
$ uname -a
Linux CoreBook 6.8.0-40-generic #40-Ubuntu SMP PREEMPT_DYNAMIC Fri Jul  5 10:34:03 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
$ cat t.c
// #define _XOPEN_SOURCE		// for testing
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

int
main(void)
{
    struct tm tm;
    char buf[255];

    memset(&tm, 0, sizeof(tm));
    strptime("2001-11-12 18:31:01", "%Y-%m-%d %H:%M:%S", &tm);
    strftime(buf, sizeof(buf), "%d %b %Y %H:%M", &tm);
    puts(buf);
    exit(EXIT_SUCCESS);
}
$ cc -Wall -Werror -o /dev/null t.c
t.c: In function ʽmainʼ:
t.c:14:5: error: implicit declaration of function ʽstrptimeʼ; did you mean ʽstrftimeʼ? [-Werror=implicit-function-declaration]
   14 |     strptime("2001-11-12 18:31:01", "%Y-%m-%d %H:%M:%S", &tm);
      |     ^~~~~~~~
      |     strftime
cc1: all warnings being treated as errors
$ cc -D_XOPEN_SOURCE -Wall -Werror -o /dev/null t.c
$
```

It's been like this on Linux for years and years now.

-RVP