GWT 2.8.2 to 2.9.0 - Possible problem with your *.gwt.xml module file.The compile time user.agent value (safari) does not match the runtime user.agent value (gecko1_8).Expect more errors.

[Freddy Boucher]

Hi,

So I upgraded our app from GWT 2.8.2 to 2.9.0 and I'm facing an issue with Firefox (it's a GXT 4.0.3 app but I don't think it's relevant in this issue)

It throws an Exception:

Possible problem with your *.gwt.xml module file.The compile time user.agent value (safari) does not match the runtime user.agent value (gecko1_8).Expect more errors.

I can fix this issue by adding:

<set-configuration-property name="user.agent.runtimeWarning" value="false"/>

But I'd like to understand the root cause of this issue.

So I did some investigations and when I call: 

System.getProperty("user.agent")

In my client code 

• with GWT 2.8.2, it returns gecko1_8
• with GWT 2.9.0, it returns safari

But in both cases the backend picks-up the gecko1_8 permutation (I check it in compilation-mappings.txt).

Did GWT 2.9.0 introduce anything that could cause this behavior?

Thank you

[Freddy Boucher]

Oh I didn't notice it, but my demo app is also broken with Firefox:

Try it with Firefox: https://gwt-storage-objectify.appspot.com/?compiler.stackMode=emulated

Github repo: https://github.com/freddyboucher/gwt-storage-objectify

[Freddy Boucher]

Ok I found the culprit!

It's the gwt-bean-validators library.

It's this particular commit: https://gitlab.com/ManfredTremmel/gwt-bean-validators/-/commit/da32e4003f6a55b12a3ac16cae7576b80e6749fd
They force the safari permutation for every browser:

<set-property name="user.agent" value="safari"/>

I can workaround it by updating my Module and set it back to original value like:

<set-property name="user.agent" value="ie8,gecko1_8,safari,ie9,ie10"/>

I'm going to report this issue to gwt-bean-validators.

Freddy