Additional info:
[2019-12-13 22:26:58,876] INFO Installing erp5.
[2019-12-13 22:26:58,876] INFO Warning: "branch" parameter with value "master" is ignored. Checking out to revision 80994259537cc30d255d9230aabaf47dce621bf8.
[2019-12-13 22:26:58,876] INFO Cloning into '/opt/slapgrid/5b41896bce906eba84123c9581f4751d/parts/erp5'...
[2019-12-13 22:26:58,876] INFO Checking out files: 17% (14910/83621)
....
.....
Checking out files: 88% (3310/3761)
fatal: not a git repository: ../.git/modules/doc-bt5
[2019-12-13 22:26:58,877] INFO fatal: could not reset submodule index
[2019-12-13 22:26:58,877] INFO While:
[2019-12-13 22:26:58,877] INFO Installing erp5.
[2019-12-13 22:26:58,877] INFO Error: Impossible to clone repository.