Two reasons for this:
1. Document builds can fail without it even when using pdftex.
From dblatex -d -D:
Build uwm-pc-user-guide.pdf
pdflatex failed
Unexpected error occured
Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/dbtexmf/core/dbtex.py", line 332, in compile
donefiles = self._compile()
File "/usr/local/lib/python2.7/site-packages/dbtexmf/core/dbtex.py", line 400, in _compile
self.make_bin()
File "/usr/local/lib/python2.7/site-packages/dbtexmf/core/dbtex.py", line 317, in make_bin
batch=self.texbatch)
File "/usr/local/lib/python2.7/site-packages/dbtexmf/dblatex/runtex.py", line 113, in compile
self.texer.compile(texfile)
File "/usr/local/lib/python2.7/site-packages/dbtexmf/dblatex/grubber/texbuilder.py", line 73, in compile
raise OSError("%s compilation failed" % self.tex.program)
OSError: pdflatex compilation failed
/tmp/tmpe0bJK0 not removed
From tail -n 11 /tmp/tmpe0bJK0/uwm-pc-user-guide.log:
Here is how much of TeX's memory you used:
22571 strings out of 493117
331796 string characters out of 6138550
659827 words of memory out of 5000000
19593 multiletter control sequences out of 15000+600000
89643 words of font info for 150 fonts, out of 8000000 for 9000
1141 hyphenation exceptions out of 8191
48i,21n,51p,484b,2429s stack positions out of 5000i,2500n,10000p,300000b,80000s
!pdfTeX error: pdflatex (file 8r.enc): cannot open encoding file for reading
==> Fatal error occurred, no output PDF file produced!
2. dvips is a valid backend to specify with dblatex -b.
PR: 201592
Submitted by: Jason Bacon <bacon4000@gmail.com>
MFH: 2016Q1
bc44590a0e