$> scalac -Wconf:help
Configure compiler warnings.
Syntax: -Wconf:<filters>:<action>,<filters>:<action>,...
multiple <filters> are combined with &, i.e., <filter>&...&<filter>

Note: Run with `-Wconf:any:warning-verbose` to print warnings with their category, site,
and (for deprecations) origin and since-version.

<filter>
  - Any message: any

  - Message categories: cat=deprecation, cat=lint, cat=lint-infer-any
    The full list of warning categories is shown at the end of this help text.

  - Message content: msg=regex
    The regex need only match some part of the message, not all of it.

  - Site where the warning is triggered: site=my\.package\..*
    The regex must match the full name (`package.Class.method`) of the warning position.

  - Source file name: src=src_managed/.*
    If `-rootdir` is specified, the regex must match the canonical path relative to the
    root directory. Otherwise, the regex must match the canonical path relative to any
    path segment (`b/.*Test.scala` matches `/a/b/XTest.scala` but not `/ab/Test.scala`).
    Use unix-style paths, separated by `/`.

  - Origin of deprecation: origin=external\.package\..*
    The regex must match the full name (`package.Class.method`) of the deprecated entity.

  - Since of deprecation: since<1.24
    Valid operators: <, =, >, valid versions: N, N.M, N.M.P. Compares against the first
    version of the form N, N.M or N.M.P found in the `since` parameter of the deprecation,
    for example `1.2.3` in `@deprecated("", "some lib 1.2.3-foo")`.

<action>
  - error / e
  - warning / w
  - warning-summary / ws (summary with the number of warnings, like for deprecations)
  - warning-verbose / wv (show warning category and site)
  - info / i             (infos are not counted as warnings and don't affect `-Werror`)
  - info-summary / is
  - info-verbose / iv
  - silent / s

The default configuration is:
  -Wconf:cat=deprecation:ws,cat=feature:ws,cat=optimizer:ws

User-defined configurations are added to the left. The leftmost rule matching
a warning message defines the action.

Examples:
  - change every warning into an error: -Wconf:any:error
  - silence certain deprecations: -Wconf:origin=some\.lib\..*&since>2.2:s

Full list of message categories:
 - deprecation
 - feature, feature-dynamics, feature-existentials, feature-higher-kinds, feature-implicit-conversions, feature-macros, feature-postfix-ops, feature-reflective-calls
 - java-source
 - lint, lint-adapted-args, lint-byname-implicit, lint-constant, lint-delayedinit-select, lint-deprecation, lint-doc-detached, lint-eta-sam, lint-eta-zero, lint-implicit-not-found, lint-inaccessible, lint-infer-any, lint-missing-interpolator, lint-nonlocal-return, lint-nullary-override, lint-nullary-unit, lint-option-implicit, lint-package-object-classes, lint-poly-implicit-overload, lint-private-shadow, lint-recurse-with-default, lint-serial, lint-stars-align, lint-type-parameter-shadow, lint-unit-specialization
 - optimizer
 - other, other-debug, other-match-analysis, other-migration, other-pure-statement, other-shadowing
 - scaladoc
 - unchecked
 - unused, unused-imports, unused-locals, unused-nowarn, unused-params, unused-pat-vars, unused-privates
 - w-flag, w-flag-dead-code, w-flag-extra-implicit, w-flag-numeric-widen, w-flag-self-implicit, w-flag-value-discard

To suppress warnings locally, use the `scala.annotation.nowarn` annotation.

Note: on the command-line you might need to quote configurations containing `*` or `&`
to prevent the shell from expanding patterns.