# Versions Compatibility and RAILS\_GEM\_VERSION **URL:** \ **Category:** Rails\ **Created:** [August 15, 2006, 8:05am UTC](https://www.ruby-forum.com/t/versions-compatibility-and-rails-gem-version/64615 "2006-08-15T08:05:53Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![iseng](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/8baadc/32.png) [@iseng](https://www.ruby-forum.com/u/iseng)\ **Post date:** [August 15, 2006, 8:05am UTC](https://www.ruby-forum.com/t/versions-compatibility-and-rails-gem-version/64615/1 "2006-08-15T08:05:53Z")
Is there any problem with versions compatibility? A project I started with 1.1.2 cannot run with 1.1.4. Dreamhost recently updated their rails from 1.1.2 to 1.1.5 and 1.1.6. Needless to say I got “Application Error”. However when I changed RAILS\_GEM\_VERSION to either 1.1.5 or 1.1.6, it works. (Haven’t made a thorough checking though.) Here it seems there is no compatibility problem between 1.1.2 and 1.1.5 / 1.1.6. So if, I started with one version (e.g. 1.1.2) will it still work after rails upgrade later (e.g. 1.9.9)? What is the significance of RAILS\_GEM\_VERSION? Will changing it to other versions break my application? Is there any way to automatically set RAILS\_GEM\_VERSION to latest installed Rails version (i.e. without editing environment.rb)? Thanks ---
**Author:** ![iseng](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/8baadc/32.png) [@iseng](https://www.ruby-forum.com/u/iseng)\ **Post date:** [August 15, 2006, 1:12pm UTC](https://www.ruby-forum.com/t/versions-compatibility-and-rails-gem-version/64615/2 "2006-08-15T13:12:47Z")
I’m having a similar problem with Dreamhost - had a simple app that was previously working on Dreamhost - now it’s not working (hadn’t checked it for several weeks) and I’m getting the below - rails log - - fastcgi.crash.log - http/error.log ==\> FastCGI: comm with (dynamic) server “…/dispatch.fcgi” aborted: (first read) idle timeout (120 sec) FastCGI: incomplete headers (0 bytes) received from server “…/dispatch.fcgi” - fastcgi is executable & log files are writable - have tried “killall -9 ruby” - RAILS VERSION - Is this an issue below? $ gem list | grep rails ==\> rails (1.1.6, 1.1.5) - I did try modifying the rails version in the environment.rb file to the following but this didn’t help “RAILS\_GEM\_VERSION = ‘1.1.6’” Any ideas how to get the app going again??? Tks Iseng — wrote: > Is there any problem with versions compatibility? > > A project I started with 1.1.2 cannot run with 1.1.4. > > Dreamhost recently updated their rails from 1.1.2 to 1.1.5 and 1.1.6. > Needless to say I got “Application Error”. However when I changed > RAILS\_GEM\_VERSION to either 1.1.5 or 1.1.6, it works. (Haven’t made a > thorough checking though.) > > Here it seems there is no compatibility problem between 1.1.2 and 1.1.5 > / 1.1.6. > > So if, I started with one version (e.g. 1.1.2) will it still work after > rails upgrade later (e.g. 1.9.9)? > > What is the significance of RAILS\_GEM\_VERSION? Will changing it to other > versions break my application? > > Is there any way to automatically set RAILS\_GEM\_VERSION to latest > installed Rails version (i.e. without editing environment.rb)? > > Thanks ---
**Author:** ![iseng](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/8baadc/32.png) [@iseng](https://www.ruby-forum.com/u/iseng)\ **Post date:** [August 15, 2006, 1:32pm UTC](https://www.ruby-forum.com/t/versions-compatibility-and-rails-gem-version/64615/3 "2006-08-15T13:32:01Z")
Actually the “RAILS\_GEM\_VERSION = ‘1.1.6’” approach below DID work. Just had to issue a couple more “killall -9 ruby” commands. Can anyone explain this rails version setting in environment.rb? - why does it need to exist? - what’s the work around to avoid one’s application bombing after the host company upgrades the version of rails? Tks Greg H. wrote: > I’m having a similar problem with Dreamhost > > - had a simple app that was previously working on Dreamhost > > - now it’s not working (hadn’t checked it for several weeks) and I’m > getting the below > > - rails log - > - fastcgi.crash.log > - http/error.log ==\> > FastCGI: comm with (dynamic) server “…/dispatch.fcgi” aborted: (first > read) idle timeout (120 sec) > FastCGI: incomplete headers (0 bytes) received from server > “…/dispatch.fcgi” > > - fastcgi is executable & log files are writable > > - have tried “killall -9 ruby” > > - RAILS VERSION - Is this an issue below? > $ gem list | grep rails > ==\> rails (1.1.6, 1.1.5) > > - I did try modifying the rails version in the environment.rb file to > the following but this didn’t help > “RAILS\_GEM\_VERSION = ‘1.1.6’” > > Any ideas how to get the app going again??? > > Tks ---
**Author:** ![iseng](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/8baadc/32.png) [@iseng](https://www.ruby-forum.com/u/iseng)\ **Post date:** [August 15, 2006, 8:51pm UTC](https://www.ruby-forum.com/t/versions-compatibility-and-rails-gem-version/64615/4 "2006-08-15T20:51:32Z")
On 15/08/06, Greg H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > - what’s the work around to avoid one’s application bombing after the > host company upgrades the version of rails? Embedding rails with your app – either rake freeze\_gems or rake freeze\_edge as appropriate. Then you’re not using the host company’s version of rails.