fail to install on ruby-head 2.0

[zhangpy]

$ruby -v
ruby 2.0.0dev (2011-10-26 trunk 33526) [i686-linux](OS: Ubuntu 11.10)

$ gem install rcov
Fetching: rcov-0.9.11.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing rcov:
ERROR: Failed to build gem native extension.

    .rvm/rubies/ruby-head/bin/ruby extconf.rb

creating Makefile

make
compiling 1.8/rcovrt.c
1.8/rcovrt.c:2:17: fatal error: env.h: No such file or directory
compilation terminated.
make: *** [rcovrt.o] Error 1

[drbrain]

I'm also experiencing this issue. Due to the "1.8" looks like there's an inadequate version check:

Building native extensions.  This could take a while...
rake aborted!
ERROR: Failed to build gem native extension.

        /usr/local/bin/ruby20 extconf.rb
creating Makefile

make
compiling 1.8/callsite.c
1.8/callsite.c:2:10: fatal error: 'env.h' file not found
#include <env.h>
         ^
1 error generated.
make: *** [callsite.o] Error 1


Gem files will remain installed in /Users/drbrain/Work/git/rubygems/tmp/isolate/ruby-1.9.1/gems/rcov-0.9.11 for inspection.
Results logged to /Users/drbrain/Work/git/rubygems/tmp/isolate/ruby-1.9.1/gems/rcov-0.9.11/ext/rcovrt/gem_make.out

[drbrain]

The check in the extconf.rb is wrong:

https://github.com/relevance/rcov/blob/master/ext/rcovrt/extconf.rb#L8

Should be if RUBY_VERSION > "1.9"

Same for https://github.com/relevance/rcov/blob/master/ext/rcovrt/extconf.rb#L15

[abedra]

1.9+ support has been completely removed. If you are on 1.9 or higher, you should be using simplecov

[fahimbabarpatel]

facing same issue
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /home/.rvm/rubies/ruby-2.0.0-p0/bin/ruby extconf.rb 

creating Makefile

make
compiling 1.8/rcovrt.c
1.8/rcovrt.c:2:17: fatal error: env.h: No such file or directory
compilation terminated.
make: *** [rcovrt.o] Error

[rennhak]

If you run into this problem make sure to install the simplecov-rcov gem which provides the needed env.h for the latter ruby versions.

[benallfree]

@rennhak Installing simplecov-rcov didn't fix the env.h problem for me on OS X 10.9

[abedra]

You need to switch to simplecov completely. RCov won't work properly in 2.0 or 1.9