hg-fast-export supports migrating mercurial subrepositories in the repository being converted into git submodules in the converted repository.
Git submodules must be git repositories while mercurial's subrepositories can be git, mercurial or subversion repositories. hg-fast-export will handle any git subrepositories automatically, any other kinds must first be converted to git repositories. Currently hg-fast-export does not support the conversion of subversion subrepositories. The rest of this page covers the conversion of mercurial subrepositories which require some manual steps:
The first step for mercurial subrepositories involves converting the subrepository into a git repository using hg-fast-export. When all subrepositories have been converted, a mapping file that maps the mercurial subrepository path to a converted git submodule path must be created. The format for this file is:
""="" ""="" ...
The path of this mapping file is then provided with the --subrepo-map command line option.
Example mercurial repo folder structure (~/mercurial): src/... subrepo/subrepo1 subrepo/subrepo2
Create an empty new folder where all the converted git modules will be imported: mkdir ~/imported-gits cd ~/imported-gits
mkdir submodule1
cd submodule1
git init
hg-fast-export.sh -r ~/mercurial/subrepo1
cd ..
mkdir submodule2
cd submodule2
git init
hg-fast-export.sh -r ~/mercurial/subrepo2
cd ~/imported-gits
cat > submodule-mappings << EOF
"subrepo/subrepo1"="../submodule1"
"subrepo/subrepo2"="../submodule2"
EOF
cd ~/imported-gits
mkdir git-main-repo
cd git-main-repo
git init
hg-fast-export.sh -r ~/mercurial --subrepo-map=../submodule-mappings
The resulting repository will now contain the subrepo/subrepo1 and subrepo/subrepo1 submodules. The created .gitmodules file will look like:
[submodule "subrepo/subrepo1"]
path = subrepo/subrepo1
url = ../submodule1
[submodule "subrepo/subrepo2"]
path = subrepo/subrepo2
url = ../submodule2