cubicweb #15505460 datafeed source pull silently fails if parser cannot be found [validation pending]

import logs keep accumulating in the "imports" tab of CWSource primary view, no "last synchronization time" gets set.

such an error should be reported both on the server and to the end user in the UI.

prioritynormal
typebug
done in3.24.0
load0.500
load left0.000
closed by#dabbb2a4a493 [datafeed] Complete the import log even if parser could not be found
patch[datafeed] Complete the import log even if parser could not be found [applied]