proj_create_from_database: ellipsoid not found

I am used to ignore Proj warnings, which are frequent when some geospatial data has some little irregularities in metadatas.

But ... I am using S1Tiling on HAL, and I noticed an ERROR message when SARCalibration or ResetMargin are called (I can't say exactly which one throws the error).

DEBUG - Register app: ResetMargin (from app) -ram '4096' -threshold.x 1000 -threshold.y.start 0 -threshold.y.end 0
INFO - 2020-12-03 08:34:01 (INFO) ResetMargin: Default RAM limit for OTB is 256 MB
INFO - 2020-12-03 08:34:01 (INFO) ResetMargin: GDAL maximum cache size is 12847 MB
INFO - 2020-12-03 08:34:01 (INFO) ResetMargin: OTB will use at most 4 threads
ERROR 1: PROJ: proj_create_from_database: ellipsoid not found