installing hhvm specific release - hhvm

Question

for few times now i've been following this guidance trying to install hhvm 3.9 on my system, which is as follows :
RELEASE=17.2
CODENAME=rafaela
EDITION="Cinnamon 64-bit"
DESCRIPTION="Linux Mint 17.2 Rafaela"
DESKTOP=Gnome
TOOLKIT=GTK
NEW_FEATURES_URL=http://www.linuxmint.com/rel_rafaela_cinnamon_whatsnew.php
RELEASE_NOTES_URL=http://www.linuxmint.com/rel_rafaela_cinnamon.php
USER_GUIDE_URL=help:linuxmint
GRUB_TITLE=Linux Mint 17.2 Cinnamon 64-bit
I replaced the deb line by adding the specific version i want:
sudo add-apt-repository "deb http://dl.hhvm.com/ubuntu trusty-lts-3.9 main"
and yet i always end up running hhvm --version and then get:
HipHop VM 3.10.0-dev (rel)
Compiler: heads/master-0-ge6fe4904121181791863528eef873cd31ac8fd23
Repo schema: 8b2eab7449176279799f086c56a57f084374dc0e
any idea what can i be doing wrong? or what is hiding in my system that causes this?
this is the log for trying to install the 3.6 version ( i thought to give it a try):
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
libboost-context1.54.0 libboost-filesystem1.54.0
libboost-program-options1.54.0 libboost-regex1.54.0 libboost-thread1.54.0
The following NEW packages will be installed:
hhvm libboost-context1.54.0 libboost-filesystem1.54.0
libboost-program-options1.54.0 libboost-regex1.54.0 libboost-thread1.54.0
0 upgraded, 6 newly installed, 0 to remove and 19 not upgraded.
Need to get 16.0 MB/16.4 MB of archives.
After this operation, 2,057 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://dl.hhvm.com/ubuntu/ trusty-lts-3.6/main hhvm amd64 3.6.6~trusty [16.0 MB]
Fetched 16.0 MB in 47s (336 kB/s)
Selecting previously unselected package libboost-context1.54.0:amd64.
(Reading database ... 193638 files and directories currently installed.)
Preparing to unpack .../libboost-context1.54.0_1.54.0-4ubuntu3.1_amd64.deb ...
Unpacking libboost-context1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Selecting previously unselected package libboost-filesystem1.54.0:amd64.
Preparing to unpack .../libboost-filesystem1.54.0_1.54.0-4ubuntu3.1_amd64.deb ...
Unpacking libboost-filesystem1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Selecting previously unselected package libboost-program-options1.54.0:amd64.
Preparing to unpack .../libboost-program-options1.54.0_1.54.0-4ubuntu3.1_amd64.deb ...
Unpacking libboost-program-options1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Selecting previously unselected package libboost-regex1.54.0:amd64.
Preparing to unpack .../libboost-regex1.54.0_1.54.0-4ubuntu3.1_amd64.deb ...
Unpacking libboost-regex1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Selecting previously unselected package libboost-thread1.54.0:amd64.
Preparing to unpack .../libboost-thread1.54.0_1.54.0-4ubuntu3.1_amd64.deb ...
Unpacking libboost-thread1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Selecting previously unselected package hhvm.
Preparing to unpack .../hhvm_3.6.6~trusty_amd64.deb ...
Unpacking hhvm (3.6.6~trusty) ...
Processing triggers for ureadahead (0.100.0-16) ...
ureadahead will be reprofiled on next reboot
Setting up libboost-context1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Setting up libboost-filesystem1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Setting up libboost-program-options1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Setting up libboost-regex1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Setting up libboost-thread1.54.0:amd64 (1.54.0-4ubuntu3.1) ...
Setting up hhvm (3.6.6~trusty) ...
********************************************************************
* HHVM is installed.
*
* Running PHP web scripts with HHVM is done by having your
* webserver talk to HHVM over FastCGI. Install nginx or Apache,
* and then:
* $ sudo /usr/share/hhvm/install_fastcgi.sh
* $ sudo /etc/init.d/hhvm restart
* (if using nginx) $ sudo /etc/init.d/nginx restart
* (if using apache) $ sudo /etc/init.d/apache restart
*
* Detailed FastCGI directions are online at:
* https://github.com/facebook/hhvm/wiki/FastCGI
*
* If you're using HHVM to run web scripts, you probably want it
* to start at boot:
* $ sudo update-rc.d hhvm defaults
*
* Running command-line scripts with HHVM requires no special setup:
* $ hhvm whatever.php
*
* You can use HHVM for /usr/bin/php even if you have php-cli
* installed:
* $ sudo /usr/bin/update-alternatives \
* --install /usr/bin/php php /usr/bin/hhvm 60
********************************************************************
Processing triggers for libc-bin (2.19-0ubuntu6.6) ...
this one ended up the same way.... version 3.10.0

Answer 1

Something else may be providing hhvm -- you can do which hhvm to see where it is. The one installed via apt-get should be /usr/bin/hhvm. A version you have installed yourself on top of that might be overriding it.
A couple of other notes about your output. First, this was in your output above:
Get:1 http://dl.hhvm.com/ubuntu/ trusty-lts-3.6/main hhvm amd64 3.6.6~trusty [16.0 MB]
That is different than the 3.9 source line you posted above. You should audit your apt configuration -- /etc/apt/sources.list and everything under /etc/apt/sources.list.d/ -- and see if you have multiple specifications of the HHVM repo.
Finally, note that you are using trusty, which is Ubuntu 14.04. This is not a build specifically for your Mint system. It may work, but it may not -- Mint is not an officially supported distribution for HHVM. Building from source will almost certainly work, but the binaries may not be compatible.