Assuming the builder is also used for the 5.1 branch with different parameters (not sure if this is the case?), kicad-5.1-jenkins-434-x86_64 October 19 fails to run after install with a message that libzstd.dll missing. Repeated install did not help.
kicad-5.1-jenkins-433-x86_64 October 18 worked when installed after this. and there was no problem with **kicad-5.1-jenkins-432-x86_64 installed prior to these problems.
It was the nightly of the 5.1 branch that would not run.
I installed the master Windows nightly in a VM and can confirm that it is working.
Version: (5.99.0-243-g846397c69), release build
Libraries:
wxWidgets 3.0.4
libcurl/7.66.0 OpenSSL/1.1.1d (Schannel) zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.1.1) nghttp2/1.39.2
Platform: Windows 7 (build 7601, Service Pack 1), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
Build date: Oct 19 2019 21:06:13
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
Boost: 1.71.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.66.0
Compiler: GCC 9.2.0 with C++ ABI 1013
For the 5.1. branch I also tried the kicad-5.1-jenkins-435-x86_64 nightly (Oct. 20) in my main Win7 installation. I still get the same error about the missing file when trying to launch.
So I reverted back to kicad-5.1-jenkins-433-x86_64 (Oct 18) which works.