Even simple plugins, like upgrading the EmptyPlugin, fails once JQueryCompatibitilyModePlugin? is installed and enabled. If you disable the plugin from configure, then installation works as expected.

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Could not load /var/www/foswiki100/tools/extender.pl
There was a compile error: Use of uninitialized value in pattern match (m//) at /var/www/foswiki100/lib/Foswiki.pm line 1265.
 at /var/www/foswiki100/bin/configure line 91
	main::__ANON__('Use of uninitialized value in pattern match (m//) at /var/www...') called at /var/www/foswiki100/lib/Foswiki.pm line 1265
	Foswiki::normalizeWebTopicName('Foswiki=HASH(0x95f9d70)', 'view', 'undef') called at /var/www/foswiki100/lib/Foswiki.pm line 1099
	Foswiki::getScriptUrl('Foswiki=HASH(0x95f9d70)', 1, 'undef', 'view', 'undef') called at /var/www/foswiki100/lib/Foswiki/Func.pm line 116
	Foswiki::Func::getScriptUrl('view') called at /var/www/foswiki100/lib/Foswiki/Plugins/JQueryCompatibilityModePlugin.pm line 70
	Foswiki::Plugins::JQueryCompatibilityModePlugin::initPlugin('WebHome', 'Main', 'admin', 'System') called at /var/www/foswiki100/lib/Foswiki/Plugin.pm line 231
	Foswiki::Plugin::registerHandlers('Foswiki::Plugin=HASH(0x9bbfcc4)', 'Foswiki::Plugins=HASH(0x97efde0)') called at /var/www/foswiki100/lib/Foswiki/Plugins.pm line 284
	Foswiki::Plugins::enable('Foswiki::Plugins=HASH(0x97efde0)') called at /var/www/foswiki100/lib/Foswiki.pm line 1523
	Foswiki::new('Foswiki', 'admin') called at /var/www/foswiki100/tools/extender.pl line 115
	Foswiki::Extender::BEGIN() called at /var/www/foswiki100/lib/Foswiki/Prefs.pm line 124
	eval {...} called at /var/www/foswiki100/lib/Foswiki/Prefs.pm line 124
	require /var/www/foswiki100/tools/extender.pl called at /var/www/foswiki100/EmptyPlugin_installer line 76
	require /var/www/foswiki100/EmptyPlugin_installer called at /var/www/foswiki100/lib/Foswiki/Configure/UIs/EXTEND.pm line 158
	eval {...} called at /var/www/foswiki100/lib/Foswiki/Configure/UIs/EXTEND.pm line 156
	Foswiki::Configure::UIs::EXTEND::ui('Foswiki::Configure::UIs::EXTEND=HASH(0x905a308)') called at /var/www/foswiki100/bin/configure line 561
	Foswiki::_actionInstallExtension() called at /var/www/foswiki100/bin/configure line 454
BEGIN failed--compilation aborted at /var/www/foswiki100/tools/extender.pl line 124.
 at /var/www/foswiki100/tools/extender.pl line 124
	require /var/www/foswiki100/tools/extender.pl called at /var/www/foswiki100/EmptyPlugin_installer line 76
	require /var/www/foswiki100/EmptyPlugin_installer called at /var/www/foswiki100/lib/Foswiki/Configure/UIs/EXTEND.pm line 158
	eval {...} called at /var/www/foswiki100/lib/Foswiki/Configure/UIs/EXTEND.pm line 156
	Foswiki::Configure::UIs::EXTEND::ui('Foswiki::Configure::UIs::EXTEND=HASH(0x905a308)') called at /var/www/foswiki100/bin/configure line 561
	Foswiki::_actionInstallExtension() called at /var/www/foswiki100/bin/configure line 454

(if this is a TWiki release prior to 4.2, you can download this
 file from: http://twiki.org/cgi-bin/view/Codev/ExtenderScript
 and place it in
 /var/www/foswiki100/tools
 Create the directory if necessary).
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Error when trying to eval the file content: This installer must be run from the root directory of a Foswiki installation at (eval 220) line 97.
 at /usr/lib/perl5/vendor_perl/5.8.8/CGI/Carp.pm line 356
	CGI::Carp::realdie('This installer must be run from the root directory of a Foswi...') called at /usr/lib/perl5/vendor_perl/5.8.8/CGI/Carp.pm line 437
	CGI::Carp::die('This installer must be run from the root directory of a Foswi...') called at (eval 220) line 97
	Foswiki::Extender::BEGIN() called at (eval 220) line 125
	eval {...} called at (eval 220) line 125
	eval '# Module of Foswiki - The Free and Open Source Wiki, http://foswiki.org/
...

---

Just installed a fresh foswiki stabel.

• Installed JCMP ( worked )
• Installed EP ( worked )
• Installed ACLP ( worked )
• Installed TLP ( worked )
• Instaleld TMUAP ( worked )
• upgraded TMP ( worked )

OS: ubuntu, apache2, perl v5.10.0 Foswiki: 1.0.0 stable ( fresh and clean ) ENV: SHORTURLS , all pub/ data etc dirs are on their default places. -- EugenMayer - 25 Jan 2009

ok i found the bug in the initPlugin method of JQueryCMPlugin? . I was calling Func::getScriptUrl the wrong way