Deprecate option parsing in config.ru files.

2 files changed, 2 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9918f45e..8580cd56 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -42,6 +42,7 @@ All notable changes to this project will be documented in this file. For info on
 - `Rack::Directory` allow directory traversal inside root directory. ([#1417](https://github.com/rack/rack/pull/1417), [@ThomasSevestre](https://github.com/ThomasSevestre))
 - Sort encodings by server preference. ([#1184](https://github.com/rack/rack/pull/1184), [@ioquatix](https://github.com/ioquatix), [@wjordan](https://github.com/wjordan))
 - Rework host/hostname/authority implementation in `Rack::Request`. `#host` and `#host_with_port` have been changed to correctly return IPv6 addresses formatted with square brackets, as defined by [RFC3986](https://tools.ietf.org/html/rfc3986#section-3.2.2). ([#1561](https://github.com/rack/rack/pull/1561), [@ioquatix](https://github.com/ioquatix))
+- `Rack::Builder` parsing options on first `#\` line is deprecated. ([#1574](https://github.com/rack/rack/pull/1574), [@ioquatix](https://github.com/ioquatix))
 
 ### Removed
 
diff --git a/lib/rack/builder.rb b/lib/rack/builder.rb
index 764e3f1f..816ecf62 100644
--- a/lib/rack/builder.rb
+++ b/lib/rack/builder.rb
@@ -97,6 +97,7 @@ module Rack
       cfgfile.slice!(/\A#{UTF_8_BOM}/) if cfgfile.encoding == Encoding::UTF_8
 
       if cfgfile[/^#\\(.*)/] && opts
+        warn "Parsing options from the first comment line is deprecated!"
         options = opts.parse! $1.split(/\s+/)
       end