Tor nightly fails to build for Windows
Since 2019-02-15, tor fails to build for Windows inside the Tor Browser nightly builds.
It fails with this error:
CCLD src/tools/tor-gencert.exe
CCLD src/test/test-switch-id.exe
CCLD src/test/test-timers.exe
CCLD src/test/test-bt-cl.exe
CCLD src/test/test-rng.exe
CCLD src/test/fuzz/fuzz-consensus.exe
CCLD src/test/fuzz/fuzz-descriptor.exe
CCLD src/test/fuzz/fuzz-diff.exe
CCLD src/test/fuzz/fuzz-diff-apply.exe
CCLD src/test/fuzz/fuzz-extrainfo.exe
CCLD src/test/fuzz/fuzz-hsdescv2.exe
CCLD src/test/fuzz/fuzz-hsdescv3.exe
CCLD src/test/fuzz/fuzz-http.exe
CCLD src/test/fuzz/fuzz-http-connect.exe
CCLD src/test/fuzz/fuzz-iptsv2.exe
CCLD src/test/fuzz/fuzz-microdesc.exe
CCLD src/test/fuzz/fuzz-socks.exe
CCLD src/test/fuzz/fuzz-strops.exe
CCLD src/test/fuzz/fuzz-vrs.exe
CCLD src/app/tor.exe
CCLD src/tools/tor-resolve.exe
CCLD src/tools/tor-print-ed-signing-cert.exe
CCLD src/test/bench.exe
CCLD src/test/test.exe
CCLD src/test/test-slow.exe
/var/tmp/dist/mingw-w64/lib/gcc/i686-w64-mingw32/6.4.0/../../../../i686-w64-mingw32/bin/ld: cannot find -lz
collect2: error: ld returned 1 exit status
make[1]: *** [src/test/test-slow.exe] Error 1
Makefile:8673: recipe for target 'src/test/test-slow.exe' failed
make[1]: *** Waiting for unfinished jobs....
make[1]: Leaving directory '/var/tmp/build/tor-59c3910becd9'
Makefile:5290: recipe for target 'all' failed
make: *** [all] Error 2