install -D loses some files to EEXIST

[danielzgtg]

Downstream: https://bugs.launchpad.net/ubuntu/+source/coreutils-from/+bug/2152495 . Tested with 7ea1211 and rust-coreutils=0.8.0-0ubuntu3.

Some files do not reach the destination folder if their parent directories cannot be created due to EEXIST. gnuinstall does not have this problem.

d=$(mktemp -d)
>$d/s
for i in {1..10}; do
  for k in {1..32}; do
    ~/CLionProjects/without_the_change/target/release/coreutils install -D $d/s $d/o$i/q/f$k &
  done
done
wait
fd . $d | wc -l

Replace the command with gnuinstall and the problem never occurs.

Expected behavior

There should be 341 files and no error message.

Actual behavior

I frequently only get 339 files. 2 files went missing. Console has:

[...]
install: cannot create directory '/tmp/tmp.dObRncyKbV/o8/q'
[...]
[225]   Exit 1                     ~/CLionProjects/without_the_change/target/release/coreutils install -D $d/s $d/o$i/q/f$k
[...]

Note that this is a race condition, and I have seen another wrong 340, as well as the correct 341 sometimes.