log4net affecting other projects which don't even use it

Question

I'm seeing something really strange happening with some projects I'm working on.

I used log4net in an MVC web site and this was working great.

I then was working on a totally unrelated Console application which uses the SharePoint API and as soon as I include the following line (other lines don't cause the problem)

SPLimitedWebPartManager spWebPartManager = web.GetLimitedWebPartManager("http://blah/blah.aspx?PageView=Shared", System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared);

I get the following message in the console app

log4net:ERROR XmlConfigurator: Failed to find configuration section 'log4net' in
 the application's .config file. Check your .config file for the <log4net> and <
configSections> elements. The configuration section should look like: <section n
ame="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" /
>
log4net:ERROR XmlConfigurator: Failed to find configuration section 'log4net' in
 the application's .config file. Check your .config file for the <log4net> and <
configSections> elements. The configuration section should look like: <section n
ame="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" /
>

I get this twice after a small delay. The delay is probably the request to get the web part manager from the page but I'm not sure why this log4net error is showing up in this project. I've gone through the code and bin folders etc. and found no trace of any log4net mentions.

Any ideas why this might be happening?

Answer 1

Is Log4Net in the GAC?

Does your application reference any external class libraries? Maybe one of these uses Log4Net and expects the client's config to be setup for Log4Net.

Answer 2

On the basis that stuff cannot generate errors unless it is used in some way, there must be some indirect reference to log4net in there. Are you using any third party libraries that depend on log4net, or some kind of error handling library that uses it. The most likely explanation for the error is the line of code is throwing an exception which is being caught by an error handling routine that is trying to log the error using log4net and then can't becuase there is no log4net config.