Unresolved symbols when program imports std.regex

[GrahamC]

>> If I import std.regex in a program, compiling with gdc gives many unresolved symbols, e.g for:
>>  immutable(std.internal.uni.CodepointSet) std.internal.uni_tab.unicodeLu
>>  ref @safe std.internal.uni.CodepointSet std.internal.uni.CodepointSet.add(const(std.internal.uni.CodepointSet))
>> plus many others.

I did a new download and build today and my problem is no longer happening. Maybe it was my error.

Thanks for your replies.