Hello,

	$ cat l.yaml
	---
	mylist:
	  - |
	    blablub
	  };
	$ yamllint l.yaml
	Traceback (most recent call last):
	  File "/usr/bin/yamllint", line 33, in <module>
	    sys.exit(load_entry_point('yamllint==1.26.3', 'console_scripts', 'yamllint')())
	  File "/usr/lib/python3/dist-packages/yamllint/cli.py", line 210, in run
	    prob_level = show_problems(problems, file, args_format=args.format,
	  File "/usr/lib/python3/dist-packages/yamllint/cli.py", line 106, in show_problems
	    for problem in problems:
	  File "/usr/lib/python3/dist-packages/yamllint/linter.py", line 203, in _run
	    for problem in get_cosmetic_problems(buffer, conf, filepath):
	  File "/usr/lib/python3/dist-packages/yamllint/linter.py", line 140, in get_cosmetic_problems
	    for problem in rule.check(rule_conf,
	  File "/usr/lib/python3/dist-packages/yamllint/rules/indentation.py", line 580, in check
	    for problem in _check(conf, token, prev, next, nextnext, context):
	  File "/usr/lib/python3/dist-packages/yamllint/rules/indentation.py", line 346, in _check
	    'wrong indentation: expected %d but found %d' %
	TypeError: %d format: a number is required, not NoneType

I guess the right thing to do would be to output something like:

	l.yaml
	   5:5       error    syntax error: expected <block end>, but found '}' (syntax)

(At least this is what happens if I force expected to be a number in
/usr/lib/python3/dist-packages/yamllint/rules/indentation.py", line 346)

Best regards
Uwe