Unexplained mount failure, protocol error, what we know so far

To reproduce this issue please just run sudo make install with the following Makefile

numbers=$(shell seq 100)

.PHONY: all
all: $(foreach nr,$(numbers),test-$(nr)_1_all.snap)

test-%_1_all.snap:
	mkdir test-$*
	mkdir -p test-$*/meta
	echo "name: test-$*" > test-$*/meta/snap.yaml
	echo "version: 1" >> test-$*/meta/snap.yaml
	echo $* > test-$*/id
	snap pack test-$* .

.PHONY: install 
install: $(foreach nr,$(numbers),test-$(nr)_1_all.snap)
	echo $^ | xargs -n 1 -P $(words $(numbers)) snap install --dangerous

.PHONY: clean
clean:
	rm -rf test-*.snap test-*

I also looked at util-linux and I found a bug there. I will try to fix the bug locally and see if that fixes the issue.