Redmine

I want to install Redmine on Debian Server with Plesk.
When i start the installer, i get this error message

Fetching gem metadata from https://rubygems.org/.............
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Resolving dependencies.......
Using rake 12.3.0
Using i18n 0.7.0
Using minitest 5.11.1
Using thread_safe 0.3.6
Using builder 3.2.3
Using erubis 2.7.0
Using mini_portile2 2.3.0
Using crass 1.0.3
Using rack 1.6.8
Using mime-types-data 3.2016.0521
Using arel 6.0.4
Using public_suffix 3.0.1
Using bundler 1.13.5
Using mini_mime 1.0.0
Installing ffi 1.9.18 with native extensions
Using coderay 1.1.2
Using concurrent-ruby 1.0.5
Using docile 1.1.5
Using htmlentities 4.3.4
Using thor 0.20.0
Using metaclass 0.0.4
Using mimemagic 0.3.2
Using multi_json 1.13.1
Using net-ldap 0.12.1
Using ruby-openid 2.3.0
Using rbpdf-font 1.19.1
Using rdoc 4.3.0
Installing redcarpet 3.4.0 with native extensions
Using request_store 1.0.5
Installing rmagick 2.16.0 with native extensions
Using rubyzip 1.2.1
Using websocket 1.2.5
Using simplecov-html 0.9.0
Using yard 0.9.12
Using tzinfo 1.2.4
Installing nokogiri 1.8.1 with native extensions
Using rack-test 0.6.3
Using mime-types 3.1
Using addressable 2.5.2
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
current directory:
/var/www/vhosts/domainname.de/projekte.domainname.de/vendor/bundle/ruby/2.3.0/gems/ffi-1.9.18/ext/ffi_c
/opt/plesk/ruby/2.3.6/bin/ruby -r ./siteconf20180124-4903-11fbdst.rb extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib/x86_64-linux-gnu
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/opt/plesk/ruby/2.3.6/bin/$(RUBY_BASE_NAME)
--with-ffi_c-dir
--without-ffi_c-dir
--with-ffi_c-include
--without-ffi_c-include=${ffi_c-dir}/include
--with-ffi_c-lib
--without-ffi_c-lib=${ffi_c-dir}/lib/x86_64-linux-gnu
--with-libffi-config
--without-libffi-config
--with-pkg-config
--without-pkg-config
/opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:456:in `try_do':
The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:587:in
`try_cpp'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:1091:in
`block in have_header'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:942:in
`block in checking_for'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:350:in
`block (2 levels) in postpone'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:320:in
`open'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:350:in
`block in postpone'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:320:in
`open'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:346:in
`postpone'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:941:in
`checking_for'
from /opt/plesk/ruby/2.3.6/lib/x86_64-linux-gnu/ruby/2.3.0/mkmf.rb:1090:in
`have_header'
from extconf.rb:16:in `<main>'
To see why this extension failed to compile, please check the mkmf.log which can
be found here:
/var/www/vhosts/domainname.de/projekte.domainname.de/vendor/bundle/ruby/2.3.0/extensions/x86_64-linux/2.3.0-static/ffi-1.9.18/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in
/var/www/vhosts/domainname.de/projekte.domainname.de/vendor/bundle/ruby/2.3.0/gems/ffi-1.9.18
for inspection.
Results logged to
/var/www/vhosts/domainname.de/projekte.domainname.de/vendor/bundle/ruby/2.3.0/extensions/x86_64-linux/2.3.0-static/ffi-1.9.18/gem_make.out
An error occurred while installing ffi (1.9.18), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.18'` succeeds before bundling.
Please configure your config/database.yml first
ERROR:rubymng:Command '['/opt/psa/admin/sbin/filemng', 'web22', 'exec', '/var/www/vhosts/domainname.de/projekte.domainname.de', '/bin/bash', '-l', '-c', 'bundle install --path vendor/bundle']' returned non-zero exit status 5



When i run `gem install ffi -v '1.9.18'` on console, i get no error.

root@plesk2 ~ # gem install ffi -v '1.9.18'
Building native extensions. This could take a while...
Successfully installed ffi-1.9.18
1 gem installed
Installing ri documentation for ffi-1.9.18...
Installing RDoc documentation for ffi-1.9.18...


Can anybody help me?