[OE-core] How to use externalsrc with git workspace

[Cliff Brake]

Hi,

In the past (say Dora era), I've used externalsrc like:

====================
DESCRIPTION = "MyApp"
LICENSE = "CLOSED"

inherit externalsrc

SRCREV = "${AUTOREV}"
PV = "1.4+gitr${SRCPV}"
PR = "r1"

SRC_URI = "git://${FILE_DIRNAME};protocol=file;branch=HEAD"
S = "${FILE_DIRNAME}"

...
====================

This was very nice in that it set SRCPV to to the git version of the HEAD of my
local workspace.  When building from a local git workspace, this makes sense to
me -- I want the Git version of the workspace, not a remote version.

Now with Jethro, I get errors like:

ERROR: ExpansionError during parsing myapp.bb: Failure expanding variable SRCPV,
expression was ${@bb.fetch2.get_srcrev(d)} which triggered exception FetchError:
Fetcher failure: Unable to resolve 'HEAD' in upstream git repository in git
ls-remote output for /scratch/externalsrc/MyApp

Do you have any suggestions how to use externalsrc + a local git workspace and
avoid the above error.  I can set branch=master, etc and bitbake will then parse
it, but the remote master version is not really what I'm building.

Thanks,
Cliff