hole in type application: is accepted, but should give error, with informative message
ghci (9.6.2) is silent about holes in type applications:
ghci> (<>) @[ _ ] "foo" "bar"
"foobar"
while it prints the substitution for holes in types, and errs:
ghci> (<>) "foo" "bar" :: [ _ ]
<interactive>:12:24: error: [GHC-88464]
• Found type wildcard ‘_’ standing for ‘Char’