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I am running ruby1.9 on Debian 5, and did not manage to install 'unicorn' with rubygems. I got this error and do not really know how to solve it.

Do you have any idea of the possible root cause ?

> gem install unicorn

Building native extensions.  This could take a while...
ERROR:  Error installing unicorn:
ERROR: Failed to build gem native extension.

    /usr/bin/ruby1.9 extconf.rb
checking for CLOCK_MONOTONIC in time.h... yes
checking for clockid_t in time.h... yes
checking for clock_gettime() in -lrt... yes
checking for t_open() in -lnsl... no
checking for socket() in -lsocket... no
checking for poll() in poll.h... yes
checking for getaddrinfo() in sys/types.h,sys/socket.h,netdb.h... yes
checking for getnameinfo() in sys/types.h,sys/socket.h,netdb.h... yes
checking for struct sockaddr_storage in sys/types.h,sys/socket.h... yes
checking for accept4() in sys/socket.h... no
checking for sys/select.h... yes
checking for ruby/io.h... yes
checking for rb_io_t.fd in ruby.h,ruby/io.h... yes
checking for rb_io_t.mode in ruby.h,ruby/io.h... yes
checking for rb_io_t.pathv in ruby.h,ruby/io.h... no
checking for struct RFile in ruby.h,ruby/io.h... yes
checking size of struct RFile in ruby.h,ruby/io.h... 24
checking for struct RObject... no
checking size of int... 4
checking for rb_io_ascii8bit_binmode()... no
checking for rb_thread_blocking_region()... yes
checking for rb_thread_io_blocking_region()... no
checking for rb_str_set_len()... yes
checking for rb_time_interval()... yes
checking for rb_wait_for_single_fd()... no
creating Makefile


poll.c:11:18: error: st.h: No such file or directory
poll.c: In function 'do_poll':
poll.c:148: error: 'RUBY_UBF_IO' undeclared (first use in this function)
poll.c:148: error: (Each undeclared identifier is reported only once
poll.c:148: error: for each function it appears in.)
make: *** [poll.o] Error 1

Gem files will remain installed in /usr/lib/ruby/gems/1.9.0/gems/kgio-2.5.0 for inspection.
Results logged to /usr/lib/ruby/gems/1.9.0/gems/kgio-2.5.0/ext/kgio/gem_make.out
share|improve this question

It looks like there are several different st.h header files out there, but given that you're missing RUBY_* constants, I'm guessing you're missing the st.h file in ruby1.9.1-dev

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I use 1.9.0 version of ruby, do you think this can be linked ? – Luc Jun 27 '11 at 16:02
Well, wherever you got that version of ruby from, you should be able to get the -dev package from the same place. If you didn't install from a package, then you're going to have to figure out how to get the headers from whatever you installed from, to wherever this is looking for them (looks like /usr/include/ruby-1.9.0/). – DerfK Jun 27 '11 at 17:22

check the zombie process ps aux | grep unicorn if it is kill the master process by kill -9 processid try to install it again. i hope it will help

share|improve this answer
Zombie processes are processes which exited, but whose parent hasn't collected the exit status. So they are a symptom of badly written parent processes. By themselves, they consume a trivial amount of system resources (a PID, and a skeleton process descriptor containing the exit status and reason), so they aren't worrisome as such, only as a signal of badly written programs. – vonbrand Jun 22 '14 at 2:14

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