Thanks for this information. The buildbot, however, fails to compile
C99 extern inline functions. Example:

ld: 0711-317 ERROR: Undefined symbol: .mpd_issnan


I understand the C99 extern inline feature like in this explanation:

https://www.greenend.org.uk/rjk/tech/inline.html


"""
In this example, one of the declarations does not mention inline:

// a declaration not mentioning inline
int max(int a, int b);

// a definition mentioning inline
inline int max(int a, int b) {
  return a > b ? a : b;
}

In either example, the function will be callable from other files.
"""



This is the scheme that libmpdec uses and that compilers understood
at the time I wrote it.