[regression] Error: expected a hex digit, but found: ' (with '\xa')

[timotheecour]

# Error: expected a hex digit, but found: '
echo "foo" & '\xa' & "bar"

[LemonBoy]

Not a bug, here's a quote from #9390

\uHHHH and \xHH must now use exactly four/two hex digits (already documented in the spec)

[timotheecour]

for people running into this:
the fix is to use '\x0a' (not '\xa0' !)