I'm writing a repository conversion tool. The problem is the git-to-darcs part. Git can have empty commits; Darcs can't. For empty Mercurial commits, I just created a tag. I know Darcs has tags, but I can't figure out how to remove the tagged prefix from the messages.
You can trick Darcs into making an empty patch by creating a non-empty patch and then using amend-record to add an inverse change to it:
ganesh@scafell ~/temp/1
$ touch foo
ganesh@scafell ~/temp/1
$ darcs add foo
Adding 'foo'
ganesh@scafell ~/temp/1
$ darcs rec
addfile ./foo
Shall I record this change? (1/1) [ynW...], or ? for more options: y
Do you want to record these changes? [Yglqk...], or ? for more options: y
What is the patch name? foo
Finished recording patch 'foo'
ganesh@scafell ~/temp/1
$ rm foo
ganesh@scafell ~/temp/1
$ darcs amend
Wed May 28 06:49:22 GMT Daylight Time 2014 Ganesh Sittampalam <ganesh@earth.li>
* foo
Shall I amend this patch? [yNjk...], or ? for more options: y
rmfile ./foo
Shall I record this change? (1/1) [ynW...], or ? for more options: y
Do you want to record these changes? [Yglqk...], or ? for more options: y
Finished amending patch:
Wed May 28 06:49:31 GMT Daylight Time 2014 Ganesh Sittampalam <ganesh@earth.li>
* foo