Issue #10409 has been reported by Masahiro Ide.

----------------------------------------
Bug #10409: Can't build Ruby checked out from official GitHub mirror
https://bugs.ruby-lang.org/issues/10409

* Author: Masahiro Ide
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: current: 2.2.0
* ruby -v: ruby 2.2.0dev (2014-10-21 trunk 48070) [i686-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
When I tried to compile official github mirror version of ruby on linux system, I get the error:

~~~
$ ./configure
...
checking for broken memmem... no
checking for nroff... /usr/bin/nroff
.ext/include/i686-linux/ruby/config.h updated
ruby library version = 2.2.0
configure: creating ./config.status
config.status: creating GNUmakefile
config.status: creating Makefile
config.status: creating ruby-2.2.pc
Downloading Unicode data files...
ruby: Can't chdir to ../enc/unicode/data (fatal)
make: *** [update-unicode] Error 1
~~~

This error happens only in the git version because git don't track emtpy directories ("$(srcdir)/enc/unicode/data").

The following patch may fix this problem.

~~~
diff --git a/common.mk b/common.mk
index 09ce4a8..e41e047 100644
--- a/common.mk
+++ b/common.mk
@@ -1097,6 +1097,7 @@ update-gems: PHONY
 
 update-unicode: PHONY
 	$(ECHO) Downloading Unicode data files...
+	$(Q) $(MAKEDIRS) "$(srcdir)/enc/unicode/data"
 	$(Q) $(BASERUBY) -C "$(srcdir)/enc/unicode/data" \
 	    ../../../tool/downloader.rb -e $(ALWAYS_UPDATE_UNICODE:yes=-a) unicode \
 	    UnicodeData.txt CompositionExclusions.txt NormalizationTest.txt

~~~



-- 
https://bugs.ruby-lang.org/