[Docutils-users] Difference in custom roles between 0.13 and 0.14?

[Tim L. <ti...@ti...>]

Hi,

I'm investigating a build failure in Fedora for Pymacs
(https://github.com/pinard/Pymacs) that occurs with (Fedora
28's) Docutils 0.14, but not with (Fedora 27's) Docutils
0.13.1
(https://bugzilla.redhat.com/show_bug.cgi?id=1555730).

The .rst file in question is
https://github.com/pinard/Pymacs/blob/master/pymacs.rst.in
with two instances of "@VERSION@" replaced by "0.25".  It
gets processed with "rst2latex --use-latex-toc
--input-encoding=UTF-8 $rst $tex".  It starts with defining
custom roles as "aliases":

| .. role:: code(strong)
| .. role:: file(literal)
| .. role:: var(emphasis)

| ================================================================
| Pymacs version @VERSION@
| ================================================================

| […]

Docutils 0.13.1 is fine with this, Docutils 0.14 causes a
TeX error
(https://bugzilla.redhat.com/attachment.cgi?id=1443162):

| […]
| ! Undefined control sequence.
| <write> ...re your \protect \texttt  {\DUrolefile
|                                                   {.emacs}} file}{\thepage }...
| l.580 F
|        rom Pymacs 0.23 and upwards, Python 2.2 or better is likely needed,
| ?
| ! Emergency stop.
| […]

The .tex files differ (inter alia) by:

| --- /tmp/f27.tex        2018-06-02 10:10:17.035844460 +0000
| +++ /tmp/f28.tex        2018-06-02 10:10:02.937009242 +0000
| @@ -1,6 +1,5 @@
|  \documentclass[a4paper]{article}
|  % generated by Docutils <http://docutils.sourceforge.net/>
| -\usepackage{fixltx2e} % LaTeX patches, \textsubscript
|  \usepackage{cmap} % fix search and cut-and-paste in Acrobat
|  \usepackage{ifthen}
|  \usepackage[T1]{fontenc}
| @@ -37,14 +36,11 @@
|  % inline markup (custom roles)
|  % \DUrole{#1}{#2} tries \DUrole#1{#2}
|  \providecommand*{\DUrole}[2]{%
| -  \ifcsname DUrole#1\endcsname%
| +  % backwards compatibility: try \docutilsrole#1{#2}
| +  \ifcsname docutilsrole#1\endcsname%
| +    \csname docutilsrole#1\endcsname{#2}%
| +  \else
|      \csname DUrole#1\endcsname{#2}%
| -  \else% backwards compatibility: try \docutilsrole#1{#2}
| -    \ifcsname docutilsrole#1\endcsname%
| -      \csname docutilsrole#1\endcsname{#2}%
| -    \else%
| -      #2%
| -    \fi%
|    \fi%
|  }

| […]

My TeX is rusty, and I do not completely understand
http://docutils.sourceforge.net/docs/user/latex.html#custom-interpreted-text-roles.
Is this a bug in Docutils, or does Pymacs need to add dummy
"\newcommand{\DUrolefile}{}"s as raw LaTex?

TIA,
Tim