f'{<error descr="expression expected">}</error>'
f'{<error descr="expression expected"><error descr="type conversion, : or } expected">'</error></error>
f'{<EOLError descr="type conversion, : or } expected"></EOLError><EOLError descr="expression expected"></EOLError><EOLError descr="' expected"></EOLError>
f'{<error descr="expression expected">!</error>r}'
f'{<error descr="expression expected">:</error>2.3}'
f'{42:2.{<error descr="expression expected">}</error>}'
f'{<error descr="expression expected"> </error> }'
f'{42:{<error descr="expression expected"> </error>}}'
f'{<error descr="expression expected"> </error> :{<error descr="expression expected"><error descr="type conversion, : or } expected"> </error></error> '
f'{<error descr="expression expected"> </error>   !r:{<error descr="expression expected"> </error>  :42}}'