My answer seems to be lost, so here again:

Am Mon, 2 Mar 2015 00:48:53 +0000 schrieb David Carlisle:

>> Per accident I run into this problem with the latex2e update 2015
>> test files:
>>
>> \documentclass[]{article} \usepackage{pgffor} \foreach\x in
>> {1,...,98} % {\newcount\a}
>>
>> \usepackage{datatool} \DTLloaddb{test}{test.csv}
>>
>> \begin{document} blub \end{document}
>>
>> test.csv contains only two lines:
>>
>> test blub
>>
>>
>> When I compile this the compilations stops and asks for input
>>
>> \@dtl@line=
>>
>> and I have to kill it with ctrl+Z.
>>
> 
> Thanks for that.
> 
> The issue is the document loads etex.sty. Normally that's OK
> but here it ends up being loaded relatively late so after all the pgf
> allocations have been made using the new scheme and so the new scheme
> had already started allocating extended registers before etex package is 
> loaded, and that's currently not working safely.
> 
> One simple workaround is to use
> 
> \RequirePackage{etex} at the start.

This doesn't work. Regardless where I put the \RequirePackage{etex}, 
I get the same error. The only thing that works is suppressing etex 
altogether with

\expandafter\def\csname [log in to unmask]\endcsname{}


> Alternatively etex.sty could be adjusted to recognise the new format
> (for example an etex.sty that did nothing at all would work in this case)

That would certainly a good idea. 


-- 
Ulrike Fischer 
http://www.troubleshooting-tex.de/