I've installed DITA 1.8 and tried to install the dita-xliff roundtrip tool. I ran into the same error as you did.
SHORT STORY / SOLUTION
Download an older version of the dita-xliff roundtrip tool, install, and try again.
LONG STORY / WHY THIS HAPPENS
When running the command with the current version of the dita-xliff roundtrip tool, you see a heapload of lines dashing by (as in "the matrix"). This isn't just meaningless BS, it acutally helps debugging (it's status and error messages). Unfortunately, there are so many messages that the first ones (the ones causing the error - all that follows is just an error caused by the error usually) get lost.
So instead of having all of that matrix stuff on the console (that black thing you type the command in), you can have it written to a file. To do this, in your dita command window, go to the xliff directory, and type
ant -f build_dita2xliff.xml > output.txt 2>&1
Wait until the command finishes. You will not see any matrix stuff flying by, as it all is now written to a file.
When the command is finished, go to the xliff folder, and open the file output.txt in Notepad. The first few lines say that it can't find some files in the samples/ComstartUserGuide folder. If you navigate to that folder, you will see that the file mentioned really doesn't exist.
I copied the samples/ComstartUserGuide files over from an older installation of the dita-xliff roundtrip tool I had, and ran it again. This time, some other files were missing. So I figured I'd stop patching the obviously incomplete xliff folder and just replaced it with the older one I had laying around. That fixed the issue (well, at least now I get a "BUILD SUCCESSFUL".
IMO there is something wrong with the files offered for download on the dita-xliff roundtrip tool website. I'll notify the author, let's hope he still works on the project.
Hope this helps.
--- In firstname.lastname@example.org, "Katrin Bretscher" <katrin@...> wrote:
> 2 thoughts:
> - the dita2xliff tool needs to be installed differently depending on which version of the toolkit (1.5.x vs. 1.6.x and higher) you're running; cf. the install notes of the dita2xliff roundtrip tool. Are you sure you installed it correctly?
> - if you're sure you installed it correctly and it still doesn't work, have you thought of upgrading your DITA OT to a more current version (1.8 would be the latest)?
> --- In email@example.com, "Leigh White" <lwwhite5@> wrote:
> > I installed the dita2xliff plugins in my OT 1.5.4 installation. While trying to run the build_dita2xliff.xml build as supplied by the plugin, I get the following errors:
> > BUILD FAILED
> > C:\DITA-OT_1.5.4\demo\xliff\build_dita2xliff.xml:24: The following error occurred while executing this line:
> > C:\DITA-OT_1.5.4\build.xml:27: The following error occurred while executing this line:
> > C:\DITA-OT_1.5.4\demo\fo\build.xml:136: The following error occurred while executing this line:
> > C:\DITA-OT_1.5.4\demo\fo\build.xml:310: Warning: Could not find file C:\DITA-OT_1.5.4\demo\xliff\temp\stage1.xml to copy.
> > I have no idea why stage1.xml is not being created in the temp folder. I tried with a fresh, out of the box 1.5.4 and got the same result. Any thoughts?
> > Thanks,
> > Leigh