lintian reports a large number of warnings on xulrunner-1.9.1-dev:
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSParser.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSInput.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIWebContentHandlerRegistrar.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIFrameLoader.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSOutput.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAccessibleEvent.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXULTemplateQueryProcessor.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSParserFilter.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIFIXptr.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSSerializer.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXULTemplateRuleFilter.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMXULTextboxElement.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMSVGEvent.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXULRuntime.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAccessibleRole.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIModifyableXPointer.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXSLTProcessorPrivate.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMXULContainerElement.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSException.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXULTemplateResult.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/stable/nsIProfileChangeStatus.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIVersionComparator.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsITypeAheadFind.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsICryptoHash.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAccessibleTypes.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDocCharset.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIHandlerService.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSResourceResolver.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/imgIEncoder.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMLSSerializerFilter.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIContentURIGrouper.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIProfileChangeStatus.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIProfileUnlocker.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIChromeRegistry.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMClientInformation.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMPageTransitionEvent.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMSVGAElement.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAutoCompleteResultTypes.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIContentPrefService.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXULSortService.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/xpcIJSWeakReference.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAccessibleRelation.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIXPointer.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/stable/nsIPrefBranch2.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIAccessibleStates.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIPrefBranch2.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMGetSVGDocument.idl
W: xulrunner-1.9.1-dev: executable-not-elf-or-script ./usr/share/idl/xulrunner-1.9.1b2/unstable/nsIDOMSVGZoomEvent.idl
Please correct this package to not install these IDL files as executables.
Fix committed in the packaging branch. It will be uploaded with 1.9.1b3.