POSIX specification:
https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/errno.h.html
Portability problems fixed by Gnulib:
EOVERFLOW
is not defined
on some platforms:
OpenBSD 4.0, mingw, MSVC 9.
ENOLINK
is not defined
on some platforms:
OpenBSD 7.5, mingw, MSVC 9.
EMULTIHOP
is not defined
on some platforms:
OpenBSD 7.5, mingw, MSVC 14.
ECANCELED
is not defined on some platforms:
OpenBSD 4.0, Cygwin, mingw, MSVC 9.
ENOMSG
, EIDRM
, EPROTO
, EBADMSG
,
ENOTSUP
are not defined on some platforms:
OpenBSD 4.0, mingw, MSVC 9.
ESTALE
is not defined on some platforms:
mingw, MSVC 14.
EDQUOT
is not defined on some platforms:
NonStop Kernel, mingw, MSVC 14.
ENETRESET
, ECONNABORTED
are not defined on some
platforms:
Minix 3.1.8, mingw, MSVC 9.
EWOULDBLOCK
, ETXTBSY
, ELOOP
, ENOTSOCK
,
EDESTADDRREQ
, EMSGSIZE
, EPROTOTYPE
, ENOPROTOOPT
,
EPROTONOSUPPORT
, EOPNOTSUPP
, EAFNOSUPPORT
,
EADDRINUSE
, EADDRNOTAVAIL
, ENETDOWN
, ENETUNREACH
,
ECONNRESET
, ENOBUFS
, EISCONN
, ENOTCONN
,
ETIMEDOUT
, ECONNREFUSED
, EHOSTUNREACH
, EALREADY
,
EINPROGRESS
are not defined on some platforms:
mingw, MSVC 9.
EOWNERDEAD
, ENOTRECOVERABLE
are not defined on
some platforms:
glibc/Linux 2.3.6, glibc/Hurd 2.15, glibc/kFreeBSD 2.15,
Mac OS X 10.5, FreeBSD 6.0, NetBSD 9.3, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin, mingw without pthreads-win32, MSVC 9.
ESOCKTNOSUPPORT
is not defined on some platforms:
Haiku.
EILSEQ
is not defined on some platforms:
LynxOS 178 2.2.2.
EEXIST
and ENOTEMPTY
have the same value on
some platforms:
AIX 7.3.
Portability problems not fixed by Gnulib: