Use the vendored libxml2/libxslt for nokogiri

* Fixes #62

Author: eregon

CHANGELOG.md

@@ -25,6 +25,7 @@ Bug fixes:
 Compatibility:
 
 * Prepend the GraalVM LLVM Toolchain to `PATH` when installing gems (#1974, #1088, #1343, #1400, #1947, #1931, #1588).
+* Installing the `nokogiri` gem now defaults to use the vendored `libxml2` and `libxslt`, similar to CRuby, which means the corresponding system packages are no longer needed (#62).
 * Implemented `$LOAD_PATH.resolve_feature_path`.
 * Add `Pathname#/` alias to `Pathname#+` (#2178).
 * Fixed issue with large `Integer`s in `Math.log` (#2184).

lib/mri/mkmf.rb

@@ -48,13 +48,6 @@
   end
 end
 
-if defined?(::TruffleRuby)
-  # Always use the system libxml/libxslt for Nokogiri on TruffleRuby.  This is
-  # currently required as TruffleRuby cannot yet link to static libraries.
-  # See https://github.com/sparklemotion/nokogiri/pull/2085 when solving this.
-  ENV['NOKOGIRI_USE_SYSTEM_LIBRARIES'] = 'true'
-end
-
 if defined?(::TruffleRuby) and Truffle::Boot.get_option('cexts-prepend-toolchain-to-path')
   ENV['PATH'] = "#{RbConfig::CONFIG['toolchain_path']}:#{ENV['PATH']}"
 end