Tag Archives: ninja

Building Mozilla NSS on Windows 10

If you’re like me you may have searched the web on how to build the Mozilla Network Security Services on Windows 10. You may have found this obsolete project on Github. You may also have found the obsolete directions for Pidgin too.

On Windows the NSS build requriements are the same as for Firefox, so go look through the build instructions for Firefox on Windows. Install Visual Studio 2019 as directed, or add the packages you need with the Visual Studio Installer. And install the Mozilla Build package in the default directory.

Now that’s done, we have one more requirement left, and that’s Gyp. For Gyp, we first need Git. If you don’t have it already, install it now. At this point I’m not certain Git comes with Visual Studio 2019. It could be, but I have a separate install anyway.

All the instructions now assume you have opened an x64 Native Tools Command Prompt for VS 2019, so open one if you don’t have already.

I prefer to keep my software I build in C:\build, so that’s what the directions will indicate.

cd c:\build
git clone https://chromium.googlesource.com/external/gyp

Gyp is a Python program, so if you don’t have it already, add Python to your path. You’ll find it in C:\mozilla-build\python and also add gyp to your path, like so

set path=%path%;C:\mozilla-build\python;C:\build\gyp

Download and extract nss-3.45-with-nspr-4.21.tar.gz By the time you read this, that particular download might be obsolete, so please adjust as needed.

I use 7z for my command line examples.

cd c:\build
7z x %homepath%\Downloads\nss-3.45-with-nspr-4.21.tar.gz

That only creates the tar file, so we need to run 7z again.

7z x nss-3.45-with-nspr-4.21.tar

You may need to add vswhere to your path, and you can do that now with

set path=%path%;%ProgramFiles(x86)%\Microsoft Visual Studio\Installer

At this point we’ll need an msys shell. So still in your x64 Native Tools Command Prompt for VS 2019,

cd C:\mozilla-build\msys

In msys, cd to the place where you extracted NSS.

cd /c/build/nss-3.45/nss

And build with


And you should get a nicely compiled debug build in C:\build\nss-3.45\dist. Happy hacking with NSS.


The author can be reached at johann@myrkraverk.com.