bitcoin: libwinpthread-1.dll not found during depends build (bdb) on Windows Subsystem for Linux

Expected behavior I should be able to make the depends without an error.

Actual behavior The program extracts BDB, preprocesses BDB, and configures BDB (I think), then goes into a long list of “checking” lines (e.g. checking for fopen... yes).

The output shows checking for clock_gettime monotonic clock... then the error message below pops up (The code execution cannot proceed because libwinpthread-1.dll was not found. Reinstalling the program may fix this problem.)

I click okay and it outputs no for checking for clock_gettime monotonic clock.... The program continues running the checks and seems to finish building the depends normally. I can then do the following:

cd ..
./autogen.sh
CONFIG_SITE=$PWD/depends/x86_64-w64-mingw32/share/config.site ./configure --prefix=/
make

And it builds without error.

To reproduce I get the error every time I run it on my system.

1. Clone repository to WSL /home/billy/bitcoin
2. Follow steps at https://github.com/bitcoin/bitcoin/blob/master/doc/build-windows.md “Cross-compilation for Ubuntu and Windows Subsystem for Linux” and “Building for 64-bit Windows” up to and including make HOST=x86_64-w64-mingw32
3. Let it run until the error message (screenshot above) pops up

System information

• Bitcoin Core master, built using instructions at https://github.com/bitcoin/bitcoin/blob/master/doc/build-windows.md
• Windows 10 version 10.0.18363.719
• Ubuntu 18.04 WSL (fresh install from Microsoft Store). I also tried on a different WSL that I upgraded from Ubuntu 16.04 to 18.04
• Intel i7 processor

Other information Similar issue here: https://github.com/bitcoin/bitcoin/issues/17277

Here’s a copy of the full output from making the depends: https://gist.githubusercontent.com/billygarrison/c548ea99d3b498065c3dc1438d1561c7/raw/64359504e6bf5639396c9aa2313e73a1b0dd2ce8/out.log

And here’s a subset of that with showing just the bdb output (line 283 is where it hangs until I click OK on the error popup): https://gist.github.com/billygarrison/ebaad2b2f93c8e89281e7a1d2ce9d88b

EDIT: Removed mention of make check test failing as it is not supported in WSL.

EDIT 2: This issue only occurs if I use make HOST=x86_64-w64-mingw32, if I use it with sudo make HOST=x86_64-w64-mingw32 then it builds fine, and the output includes checking for clock_gettime monotonic clock... yes instead of no.