error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:2
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |  ^^

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:7
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |       ^^ `\x` must be followed by at least one hex digit

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:12
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |            ^^ `\X` must be followed by at least one hex digit

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:17
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |                 ^^

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:22
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |                      ^^ `\u` must be followed by exactly 4 hex digits

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:10:27
   |
10 | "\k" "\x" "\X" "\9" "\u" "\U"
   |                           ^^ `\U` must be followed by exactly 8 hex digits

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:11:2
   |
11 | "\u000" "\U0000000"
   |  ^^^^^ `\u` must be followed by exactly 4 hex digits

error: invalid escape sequence
  --> testdata/strings/bad-escape.proto:11:10
   |
11 | "\u000" "\U0000000"
   |          ^^^^^^^^^ `\U` must be followed by exactly 8 hex digits

encountered 8 errors
