This page documents running an old version (1.8.4) of mercurial but says

"(later versions need an unavaliable python module named grp)"

This is the way I did it (but am still interested to hear of alternative ways) using an Ubuntu 16.04 machine and a intel 64bit android emulator running on Windows 7, using mercurial 3.7.3

1. Using an Ubuntu system, follow these instructions for creating 2.7 version of python capable of running hg.

2. Copy python onto android device into an app files directory (so it can be executed)

   on windows host

   adb push python279.x86_64 /sdcard

   adb -e shell

   on android device

   cd /data/user/0/$SOMEAPPDIR/files

   cp -Rav /scard/python279.x86_64 .

   make python excutable

   chmod +x python279.x86_64/bin/python2.7

   set some env vars need to make python run on android

   export LD_LIBRARY_PATH=/data/user/0/$SOMEAPPDIR/files/python279.x86_64/lib

   export LD_PRELOAD=libffi.so:libbz2.so

   export PATH=$PATH:/data/user/0/$SOMEAPPDIR/files/python279.x86_64/bin

Python should now be able to be run with python2.7

3. Build mercurial on Ubuntu host.

   download mercurial 3.7.3

   uz mercurial-3.7.3.tar.gz

   cd mercurial-3.7.3 && make all

   HOME=$PWD/dist make install

4. Make minor modifications

   cd dist/mercurial-3.7.3/dist/lib/python/mercurial

   rm *.so

   cp pure/*.py .

   Edit posix.py and delete the "import grp" line.

5. copy mercurial onto android device

   on windows host

   adb push dist /sdcard

   adb -e shell

   on android device

   cd /data/user/0/$SOMEAPPDIR/files

   cp /sdcard/dist .

   alias hg to make it easy to use

   alias hg='python2.7 /data/user/0/$SOMEAPPDIR/files/dist/bin/hg'

Hg should now be possible to use on android device.

It's even possible to clone remote repos but I also had to pass the --insecure flag to bypass ssl errors.