Bug 1971 – Any SocketException causes program to segfault

strerror_r is incorrectly defined in std.c.string to return a (const char *), but in fact it returns an int (probably an error from when strerror was switched out for the threadsafe strerror_r). In linux/GDC builds SocketException calls strlen() with the return value of strerror_r, causing a segfault.

Looks like I oversimplified the problem -- see man page for strerror_r at http://linux.die.net/man/3/strerror_r There are two incompatible versions of strerror_r, the POSIX standard one returns an int and always stores the error string in the supplied buffer. The GNU specific version behaves as Phobos currently assumes, returning a char * and maybe-or-not using the supplied buffer. The POSIX standard behavior is available in GNU through a #define macro. Note that other platforms such as OS X only support the POSIX version, so I'd argue that for portability the POSIX version should be used in Phobos, or the differences should be abstracted in the D code.

This was fixed almost two years ago. https://github.com/D-Programming-Language/phobos/commit/d57e203dc9d8d4e10e1a4072076d4895eb7bcc96