Problem

Following the build instructions for WSL with Ubuntu 20.04 resulted in this error:

utiltime.cpp: In function ‘std::string FormatISO8601DateTime(int64_t)’:
utiltime.cpp:85:5: error: ‘gmtime_r’ was not declared in this scope; did you mean ‘gmtime_s’?
   85 |     gmtime_r(&time_val, &ts);
      |     ^~~~~~~~
      |     gmtime_s 

Manually changing gmtime_r to gmtime_s results in a further warning because the arguments are reversed, a sign that we're building with the Windows version that the code uses when _MSC_VER is set.

Root Cause

WSL with Ubuntu 20.04 is not building with msvc but with mingw.

Solution

Use the Windows version of this code when either _MSC_VER or __MINGW64__ is set.

(Note: I also needed to change the build command make HOST=x86_64-w64-mingw32 to CC_FOR_BUILD=x86_64-linux-gnu-gcc make HOST=x86_64-w64-mingw32 in order to build gmp, but I was not sure if I should update the docs.)

Bounty PR

None

Bounty Payment Address

sv1qqpswvjy7s9yrpcmrt3fu0kd8rutrdlq675ntyjxjzn09f965z9dutqpqgg85esvg8mhmyka5kq5vae0qnuw4428vs9d2gu4nz643jv5a72wkqqq73mnxr

Unit Testing Results

Tested on win64 mingw WSL/Ubuntu 20.04 by building successfully and running unittests successfully compared to master.