New comment by klarasm on void-packages repository

https://github.com/void-linux/void-packages/pull/29839#issuecomment-808997947

Comment:
It seems that the build fails on x86_64-musl with `XBPS_CHECK_PKGS=yes`. I have replicated this on my machine. Attaching logs from builds with and without checks. I have not noticed any problems yet, but my use of the package may not trigger it.

I have located the error in the check to the following tests in lib/printf_test.c:
```
  /* These tests fail.
   * from man 3 printf:
   *        m      (Glibc extension; supported by uClibc and musl.)  Print output of strerror(er‐
   *                      rno).  No argument is required.
   * Maybe libc problem?
  errno = 5;
  BSPRINTF(18, "Input/output error", buf, "%m");
   */
  /* printf("%m\n\0", buf);
   * outputs "I/O error" instead
   */
  /*
  errno = 0;

  BSPRINTF(18, "Input/output error", buf, "%M", 5);
  */
  /*
   * printf("%M\n\0", buf);
   * does not seem to output anything
   */
```

Anyway, the tests that do not pass don't seem very critical to the function of the package. If it's a libc issue it's a bit weird that it only manifests on x86_64 and none of the arm archs.

From musl-1.1.24 src/errno/__strerror.h:39
`E(EIO,          "I/O error")`
From man 3 errno
`       EIO             Input/output error (POSIX.1-2001).`

[bird-v2.0.8_build.log](https://github.com/void-linux/void-packages/files/6218463/bird-v2.0.8_build.log)
[bird-v2.0.8_build-with-checks.log](https://github.com/void-linux/void-packages/files/6218464/bird-v2.0.8_build-with-checks.log)
[printf_test.c.txt](https://github.com/void-linux/void-packages/files/6218550/printf_test.c.txt)