hg clone https://hg.mozilla.org/mozilla-central source/
cd source/
hg clone https://hg.mozilla.org/comm-central comm/

$ ./mach bootstrap
Please choose the version of Firefox you want to build:
  1. Firefox for Desktop Artifact Mode
  2. Firefox for Desktop
  3. GeckoView/Firefox for Android Artifact Mode
  4. GeckoView/Firefox for Android

C:\mozilla-build\start-shell.bat

hg clone https://hg.mozilla.org/mozilla-central source/
cd source/
hg clone https://hg.mozilla.org/comm-central comm/

cd your/mozilla-central
./mach bootstrap
Note on Artifact Mode:

Artifact builds download prebuilt C++ components rather than building
them locally. Artifact builds are faster!

Artifact builds are recommended for people working on Firefox or
Firefox for Android frontends, or the GeckoView Java API. They are unsuitable
for those working on C++ code. For more information see:
https://firefox-source-docs.mozilla.org/contributing/build/artifact_builds.html.

Please choose the version of Firefox you want to build:
  1. Firefox for Desktop Artifact Mode [default]
  2. Firefox for Desktop
  3. GeckoView/Firefox for Android Artifact Mode
  4. GeckoView/Firefox for Android
  5. SpiderMonkey JavaScript engine

The Firefox build system and related tools store shared, persistent state
in a common directory on the filesystem. On this machine, that directory
is:

  c:/Users/hiroakit/.mozbuild

If you would like to use a different directory, hit CTRL+c and set the
MOZBUILD_STATE_PATH environment variable to the directory you'd like to
use and re-run the bootstrapper.

Would you like to create this directory? (Yn):

Would you like to run a configuration wizard to ensure Mercurial is
optimally configured? (Yn):

To begin, press the enter/return key.

Would you like to enable these features (Yn)?
Would you like to enable these history editing extensions (Yn)?
Would you like to enable the evolve extension? (Yn)
Would you like to enable fsmonitor (Yn)?
Enable logging of commands to help diagnose bugs and performance problems (Yn)
Enable the shelve feature. Equivalent to git stash (Yn)
Would you like to activate firefoxtree (Yn)?
Would you like to activate clang-format (Yn)?
Would you like to activate js-format (Yn)?
Would you like to install the `hg show` extension and `hg wip` alias (Yn)?
Would you like to install the `hg smart-annotate` alias (Yn)?
Would you like to activate push-to-try (Yn)?
Would you like to see a diff of the changes first (Yn)?
Write changes to hgrc file (Yn)?

ac_add_options --enable-application=comm/mail
ac_add_options --with-app-basename=Thunderbird
ac_add_options --enable-debug