gnutls 3.8.0 is missing parameter type for a function which leads to the
compiler error below. This is fixed in the latest version.

/Users/jhbuild/gtk/source/gnutls-3.8.0/lib/system/certs.c:312:20: error: parameter 'status' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
int osstatus_error(status)
                   ^
/Users/jhbuild/gtk/source/gnutls-3.8.0/lib/system/certs.c:312:5: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
int osstatus_error(status)