ASP.NET MVC 4 is bundling js files in Debug Mode - asp.net-mvc

Question

"The issue is that, by default, asp.net mvc DOES NOT bundle the css and js files in debug mode. But our css and js files ARE getting bundled in the debug mode."
For some reason, all the css and js files are being bundled in debug mode. It started few days ago. We have a large team with several developers and its hard to find out what changed in the last few days because there are several changes submitted to the repository. However I didn't find any significant changes in the BundleConfig and Global.asax.cs.
When the application is running in debug mode, BundleTable.EnableOptimizations returns a false.
To my understanding when debug is set to true then bundling does not happen.
<compilation debug="true" targetFramework="4.5">
So far I haven't found a single occurrence of this issue on Google. Is this a very unique problem?
Ideally instead of a workaround I would like to fix it. Finding the cause is the actual problem here. Any pointers on where I should start looking for the fix would be appreciated. Thank you.
Edit: My question is similar to but not exactly the same as ASP.NET MVC 4 app with bundling and minification, why is minification enabled in debug mode?
Someone please remove the "This question may already have an answer here:" tag.
In my case the bundle paths are already starting with a "~"
Template:
#Styles.Render("~/Content/css")
#Scripts.Render("~/bundles/js")
Bundle Config:
bundles.Add(new Bundle("~/Content/css").Include("~/Content/*.css"));
bundles.Add(new Bundle("~/bundles/js").Include("~/Scripts/myproj.*"));

Answer 1

Try adding this in your global Application_Start()
BundleTable.EnableOptimizations = false;
So...
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
AuthConfig.RegisterAuth();
BundleTable.EnableOptimizations = false;
}

Answer 2

For me the issue was in the web.config "debug" was set to false.
<configuration>
<system.web>
<compilation debug="false" targetFramework="4.0" />

Answer 3

Try troubleshooting outside of MVC specifically.
Does this problem now transcend your entire team or just your machine? If it's the entire team at least you know the change happened somewhere in the commit cycle.
Have you rebuilt the solution? Cleaned properly? Are you running IIS, IIS Express, or Cassini? Are you absolutely certain that the site/build you're running in the debugger is not in release mode? You may be debugging a specific build that isn't being modified through the build pipeline (failed builds definitely fall under this category).
I'm using VS 2010 and MVC 4 and by default in debug mode, I see absolutely no bundling. I don't have to explicitly set anything. If you're seeing differently, something obviously has to account for it as this isn't normal behavior.
I have a feeling your best approach is the hardest: unwind your commits. Make a copy of your working directory and revert to sometime before this happened. Verify the problem does not occur in this build, don't just assume. Now checkout a commit half way between that point in time and now. Test again. If the build is still good, cut the time in half and repeat. Once you've hit the issue, you know the commit it was introduced in is somewhere between your last "good" commit and the one you're currently testing. This technique greatly simplifies isolating a problem to a specific commit. I almost never go one commit at a time unless I'm completely unsure of the code or I already have a good indication of where it might be.

Answer 4

In my case I had used
#Scripts.Render("/Bundles/scriptname")
When I replaced it with
#Scripts.Render("~/Bundles/scriptname")
it worked. The '~' made all the difference.