A leading dash (-) in the desired pattern causes ripgrep to think there is no pattern.

[Amanita-muscaria]

What version of ripgrep are you using?

12.1.1

How did you install ripgrep?

via pacman

What operating system are you using ripgrep on?

5.8.5-arch1-1

Describe your bug.

A leading dash (-) in the desired pattern causes ripgrep to think there is no pattern.

What are the steps to reproduce the behavior?

The easiest is to search through the help output of a command.
e.g. rg -h | rg "-S"

What is the actual behavior?

❯ rg -h | rg "-S"
error: The following required arguments were not provided:
    <PATTERN>

USAGE:
    
    rg [OPTIONS] PATTERN [PATH ...]
    rg [OPTIONS] [-e PATTERN ...] [-f PATTERNFILE ...] [PATH ...]
    rg [OPTIONS] --files [PATH ...]
    rg [OPTIONS] --type-list
    command | rg [OPTIONS] PATTERN

For more information try --help

What is the expected behavior?

Returns the matched line(s)

[BurntSushi]

From the man page (and the --help output):

That is, you want rg -h | rg -e -S. Alternatively, you can use the old Unix convention of --, where everything after it is always interpreted as a positional argument. e.g., rg -h | rg -- -S. Finally one other trick is to tweak the regex syntax to fool the arg parser: rg -h | rg '[-]S'.

grep has the same problems and the same work-arounds.

See also #1560, which is a duplicate of this issue.