problem with gh vs git fetch within submodule whereami

[alaingdl]

This is not directly a problem with GDL but an issue when using "gh" on U2204 for a given PR : I cannot got the submodule

Old way 1 (OK on OSX or Debian 10)

git clone https://github.com/gnudatalanguage/gdl/
cd gdl
export myPR=9999
git fetch https://github.com/gnudatalanguage/gdl pull/$myPR/head:pr$myPR
git checkout pr$myPR
./scripts/build_gdl.sh configure
git submodule update --init
./scripts/build_gdl.sh configure
...

everything fine

New way 2 on U2204

git clone https://github.com/gnudatalanguage/gdl/
cd gdl
gh pr list
gh pr checkout 9999   (9999  PR number ...)
./scripts/build_gdl.sh prep
git submodule update --init

problem : 

Sous-module 'src/whereami' (https://github.com/gpakosz/whereami) enregistré pour le chemin 'src/whereami'
Clonage dans '/home/gdl/GDL/TestPR1798/gdl/src/whereami'...
fatal: erreur distante : upload-pack: not our ref ba364cd54fd431c76c045393b6522b4bff547f50
fatal: Chemin de sous-module 'src/whereami' récupéré, mais il ne contenait pas ba364cd54fd431c76c045393b6522b4bff547f50. La récupération directe de ce commit a échoué.
fatal: 

in english ...
LANG=gb git submodule update --init
fatal: remote error: upload-pack: not our ref ba364cd54fd431c76c045393b6522b4bff547f50
fatal: Fetched in submodule path 'src/whereami', but it did not contain ba364cd54fd431c76c045393b6522b4bff547f50. Direct fetching of that commit failed.
fatal: 

Any idea ? (it was working fine months ago)

[slayoo]

That seems strange. In fact, Google has a lot of results for "remote error: upload-pack: not our ref" but I cannot find anything relevant?!

One idea: does it still err after disabling shallow option for this submodule by setting shallow = false (or removing the shallow line)? https://github.com/gnudatalanguage/gdl/blob/e1d7f28871b399741f2bef60f82028f267471048/.gitmodules#L4C1-L4C16