I tried a gst-launch-1.0 which used to work, and which works if I use ximagesrc instead of v4l2src. I got the error message below.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Failed to allocate required memory.
Additional debug info:
gstv4l2src.c(658): gst_v4l2src_decide_allocation (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
Buffer pool activation failed
I had problems with cheese too which mentioned v4l2src. The wencam works fine with obs-studio