rustc.exe depends on winpthreads · Issue #13501 · rust-lang/rust (original) (raw)
Buildbot seems to use mingw-w64 package from mingw-builds with "thread=posix" option. In this setting, libstdc++-6.dll depends on libwinpthread-1.dll. Thus llvm binaries and rustc.exe/rustdoc.exe depend on it.
The dependency can be dropped by re-installing mingw-builds with "thread=win32" option.