There are several issues about the errors that (don't) appear in response to some action (JENKINS-17401, JENKINS-13287, JENKINS-19037, possibly others) but none seem to cover the problem that the error screen is completely useless because it doesn't show the error (e.g. stacktrace).

This is also an issue if you rename it to anything other than the original namen and click the apply button.

My apologies for the badly selected example. I tried to make it easy to reproduce, and failed to test what happens when pressing Save instead.

Note that this is not about the exception with stacktrace presented when saving, but the fact that the dialog is completely useless as an error dialog.

By the way the actual exception in this case is fixed in the 4.2 release of the Templates plugin.

The originally reported issue is actually a bug in the Templates plugin, and very similar to JENKINS-17401. Jenkins is sending a redirect and the Apply handler does not expect this. The fix is just to send a warning in that case, not a redirect. Update: actually there seems to be no such redirect in the Templates plugin, so that issue probably really is what is reported here: failure to display a stack trace.

The more general issue is that if an exception is actually thrown, you get a blank error dialog. This is trivially reproduced (in Chrome at least) by configuring a freestyle project, checking Build periodically, and typing some junk into the Schedule field. In apply.js, the error-handling code using responseDialog is triggered, but it does not work.

Commenting out $(containerId).appendChild(target); fixes the problem to the extent that the error is shown in a new browser window. But then regular Apply button handling is broken.

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/java/hudson/model/Descriptor.java
http://jenkins-ci.org/commit/jenkins/9f23c0bdb3a3ed6485e161ff5c57ebba64f88035
Log:
JavaScript error when showing a FormException after Apply is clicked. Related to JENKINS-20772 but probably not the same.

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/0e8195c43d744b65e46ce5d66262e29fbdb9fb35
Log:
[FIXED JENKINS-20772] Properly render response in case Apply results in an error page.

Code changed in jenkins
User: Jesse Glick
Path:
changelog.html
http://jenkins-ci.org/commit/jenkins/c7dcb99290548f82b39846f4db431ab2ceb326ae
Log:
JENKINS-17401 JENKINS-20772 Noting.

Compare: https://github.com/jenkinsci/jenkins/compare/833c42326863...c7dcb9929054

Integrated in jenkins_main_trunk #3133
JavaScript error when showing a FormException after Apply is clicked. Related to JENKINS-20772 but probably not the same. (Revision 9f23c0bdb3a3ed6485e161ff5c57ebba64f88035)
[FIXED JENKINS-20772] Properly render response in case Apply results in an error page. (Revision 0e8195c43d744b65e46ce5d66262e29fbdb9fb35)
JENKINS-17401 JENKINS-20772 Noting. (Revision c7dcb99290548f82b39846f4db431ab2ceb326ae)

Result = SUCCESS
Jesse Glick : 9f23c0bdb3a3ed6485e161ff5c57ebba64f88035
Files :

• core/src/main/java/hudson/model/Descriptor.java

Jesse Glick : 0e8195c43d744b65e46ce5d66262e29fbdb9fb35
Files :

• core/src/main/resources/lib/form/apply/apply.js

Jesse Glick : c7dcb99290548f82b39846f4db431ab2ceb326ae
Files :

• changelog.html

Code changed in jenkins
User: Daniel Beck
Path:
core/src/main/resources/jenkins/model/Jenkins/oops.jelly
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/b856cc2434b33ed7fec3492223e141747369bba3
Log:
JENKINS-20772 Only show error message in dialog

This change removes the superfluous UI elements around the error
message if possible. Otherwise, fall back to existing behavior
of adding entire page to iframe.

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/resources/jenkins/model/Jenkins/oops.jelly
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/f8a73006e955a15ac8491301f8d2f0a6e8e4e17c
Log:
Merge pull request #1076 from daniel-beck/better-apply-dialog

JENKINS-20772 Only show error message in dialog

Compare: https://github.com/jenkinsci/jenkins/compare/28e403ac055f...f8a73006e955

Code changed in jenkins
User: Daniel Beck
Path:
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/9b947ae8a239023482b8dcdec97d37425c42be8c
Log:
JENKINS-20772 Fix scrolling

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/e292366f62e511323442a03abdcf020396cbc407
Log:
Merge pull request #1077 from daniel-beck/better-apply-dialog

JENKINS-20772 Fix scrolling

Compare: https://github.com/jenkinsci/jenkins/compare/f2e2cbeca421...e292366f62e5

Integrated in jenkins_main_trunk #3135
JENKINS-20772 Only show error message in dialog (Revision b856cc2434b33ed7fec3492223e141747369bba3)

Result = SUCCESS
daniel-beck : b856cc2434b33ed7fec3492223e141747369bba3
Files :

• core/src/main/resources/lib/form/apply/apply.js
• core/src/main/resources/jenkins/model/Jenkins/oops.jelly

Integrated in jenkins_main_trunk #3136
JENKINS-20772 Fix scrolling (Revision 9b947ae8a239023482b8dcdec97d37425c42be8c)

Result = SUCCESS
daniel-beck : 9b947ae8a239023482b8dcdec97d37425c42be8c
Files :

• core/src/main/resources/lib/form/apply/apply.js

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/java/hudson/model/Descriptor.java
http://jenkins-ci.org/commit/jenkins/5d192634bb968190cb75cb752ed97474c57dc938
Log:
JavaScript error when showing a FormException after Apply is clicked. Related to JENKINS-20772 but probably not the same.
(cherry picked from commit 9f23c0bdb3a3ed6485e161ff5c57ebba64f88035)

Code changed in jenkins
User: Jesse Glick
Path:
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/eec3d65cdf865bcd19edae15d0ca6e581553db78
Log:
[FIXED JENKINS-20772] Properly render response in case Apply results in an error page.
(cherry picked from commit 0e8195c43d744b65e46ce5d66262e29fbdb9fb35)

Code changed in jenkins
User: Jesse Glick
Path:
http://jenkins-ci.org/commit/jenkins/de78db8d6ba0a4ca1b4b839ab9606cd151d446be
Log:
JENKINS-17401 JENKINS-20772 Noting.

(cherry picked from commit c7dcb99290548f82b39846f4db431ab2ceb326ae)

Conflicts:
changelog.html

Compare: https://github.com/jenkinsci/jenkins/compare/9144cec099bf...de78db8d6ba0

This wasn't backported completely to the 1.532.2 RC. My improvements are missing, so the error dialog cannot be scrolled and shows an entire Jenkins page with header, sidebar, and everything.

Right, but the most critical fix—showing something in the error dialog—was backported. I think we can live with that, unless the lack of scrolling is making it impossible to see error details. (See https://github.com/jglick/jenkins/compare/printStackTrace-JDK-6507809 for another angle on this.)

Exactly, scrolling is the problem here. Attached some screenshots. "unscrollable-framed" is how it's currently backported to 1.532.2-RC, "scrollable-plain" is how it was released in 1.546. Note the scroll bar It's basically useless on a ~19" screen with 1280x1024, and even the larger screen just adds more frames from servlet filters and winstone. You effectively only get the message of the first wrapped exception, which is probably much less useful than this example in many cases.

Your inversion of stack traces looks really interesting as well and would make them much more accessible in general. For reference, program in comment to linked JDK issue (slightly modified to fit in one file) produces following output:

$ java Throwable_printStackTrace
Throwable_printStackTrace$LowLevelException
	at Throwable_printStackTrace.e(Throwable_printStackTrace.java:31)
	at Throwable_printStackTrace.d(Throwable_printStackTrace.java:28)
	at Throwable_printStackTrace.c(Throwable_printStackTrace.java:22)
Caused: Throwable_printStackTrace$MidLevelException
	at Throwable_printStackTrace.c(Throwable_printStackTrace.java:24)
	at Throwable_printStackTrace.b(Throwable_printStackTrace.java:18)
	at Throwable_printStackTrace.a(Throwable_printStackTrace.java:12)
Caused: Throwable_printStackTrace$HighLevelException
	at Throwable_printStackTrace.a(Throwable_printStackTrace.java:14)
	at Throwable_printStackTrace.main(Throwable_printStackTrace.java:5)

Code changed in jenkins
User: Daniel Beck
Path:
core/src/main/resources/jenkins/model/Jenkins/oops.jelly
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/fb738ea6de6bbcc7480705d53995cd8ec88e6f40
Log:
JENKINS-20772 Only show error message in dialog

This change removes the superfluous UI elements around the error
message if possible. Otherwise, fall back to existing behavior
of adding entire page to iframe.

(cherry picked from commit b856cc2434b33ed7fec3492223e141747369bba3)

Code changed in jenkins
User: Daniel Beck
Path:
core/src/main/resources/lib/form/apply/apply.js
http://jenkins-ci.org/commit/jenkins/7b9b7ac162d9ae5acbb313d08b69a8f71ab08804
Log:
JENKINS-20772 Fix scrolling

(cherry picked from commit 9b947ae8a239023482b8dcdec97d37425c42be8c)

Compare: https://github.com/jenkinsci/jenkins/compare/867a35523c2f...7b9b7ac162d9

Code changed in jenkins
User: Jesse Glick
Path:
war/src/main/webapp/scripts/hudson-behavior.js
http://jenkins-ci.org/commit/jenkins/9620057a58dc07b52752683a433e200f36d4317d
Log:
When a server error is caught by applyErrorMessage (“ERROR” link), do not render the whole oops.jelly page.
Just pick out the <div id="error-description"> from JENKINS-20772.

Compare: https://github.com/jenkinsci/jenkins/compare/7ddc6be48716...9620057a58dc