[Resolved]Migration mail

Hello,

I am making a new raspberry+jessie +yunohost 2.4 machine in order to migrate from my old rapsberry+wheezy+yunohost2.2
I saw this page to copy all the mails for users: https://yunohost.org/#/email_migration_fr

'I’m running on Ubuntu 16.04
SO I install ruby and gem and then

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

    current directory: /var/lib/gems/2.3.0/gems/sqlite3-1.3.12/ext/sqlite3
/usr/bin/ruby2.3 -r ./siteconf20161211-357-1h2ii94.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/sqlite3-1.3.12 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/sqlite3-1.3.12/gem_make.out

could you help please?

thx

I’m responding to myself

there is some prerequisites:

sudo apt-get ruby-dev libsqlite3-dev gem

before