Dear Sir/Madam,

The 'accepted' approach to building and installing WARs using the Catalina Ant 
tasks, after first starting Tomcat, is...

<taskdef name="install" classname="org.apache.catalina.ant.InstallTask"/>

<install url="${tomcat.manager}"
            username="${tomcat.username}"
            password="${tomcat.password}"
            path="/${tomcat.app}"
            war="file://${builddir}/myapp.war"/>

...however this will FAIL on subsequent builds (without restarting Tomcat) with 
an 'application already installed' BuildException, so the subsequent 'accepted' 
approach is...

<taskdef name="install" classname="org.apache.catalina.ant.RemoveTask"/>
<taskdef name="install" classname="org.apache.catalina.ant.InstallTask"/>

<remove url="${tomcat.manager}"
            username="${tomcat.username}"
            password="${tomcat.password}"
            path="/${tomcat.app}"/>

<install url="${tomcat.manager}"
            username="${tomcat.username}"
            password="${tomcat.password}"
            path="/${tomcat.app}"
            war="file://${builddir}/myapp.war"/>

It should be noted that, equally, this latter approach will FAIL the first time 
in (with a 'no application to remove' BuildException).

Having to toggle between these two approaches every 'development session' (the 
former the first time in, the latter all subsequent times before restarting 
Tomcat) is very unproductive.

None of the 'accepted' docs seem to address this problem, so either I am being 
an idiot (very possible :) or we could really do with a, say, 'ignoreFailure' 
parameter in AbstractCatalinaTask (that simply catches the Exception, logs it, 
but does not stop the build for it).

That way we could use the latter build script every time, making things much 
easier for us all :)

Many thanks for your time,