Package throws errors with MacTeX 2018 / pdflatex

[beastaugh]

I recently installed MacTeX 2018 and am now getting errors when trying to compile documents that use the rec-thy package using pdflatex.

Here's a minimal working example:

\documentclass{article}
\usepackage{rec-thy}
\begin{document}
\end{document}

And here's the console output I get when running pdflatex on that example, along with the full log file:

$ pdflatex min-working-example.tex 
This is pdfTeX, Version 3.14159265-2.6-1.40.19 (TeX Live 2018) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
(./min-working-example.tex
LaTeX2e <2018-04-01> patch level 2
Babel <3.18> and hyphenation patterns for 84 language(s) loaded.
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/size10.clo))
(/usr/local/texlive/2018/texmf-dist/tex/latex/rec-thy/rec-thy.sty
(/usr/local/texlive/2018/texmf-dist/tex/generic/oberdiek/ltxcmds.sty)
(/usr/local/texlive/2018/texmf-dist/tex/generic/ifxetex/ifxetex.sty)
(/usr/local/texlive/2018/texmf-dist/tex/generic/oberdiek/ifpdf.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/bigfoot/suffix.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/ifmtarg/ifmtarg.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/xifthen/xifthen.sty
(/usr/local/texlive/2018/texmf-dist/tex/latex/tools/calc.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/ifthen.sty))
(/usr/local/texlive/2018/texmf-dist/tex/latex/xkeyval/xkeyval.sty
(/usr/local/texlive/2018/texmf-dist/tex/generic/xkeyval/xkeyval.tex
(/usr/local/texlive/2018/texmf-dist/tex/generic/xkeyval/xkvutils.tex
(/usr/local/texlive/2018/texmf-dist/tex/generic/xkeyval/keyval.tex))))
(/usr/local/texlive/2018/texmf-dist/tex/latex/etoolbox/etoolbox.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/expl3.sty
(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/expl3-code.tex)
(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/l3pdfmode.def))))
(/usr/local/texlive/2018/texmf-dist/tex/latex/enumitem/enumitem.sty)
! Undefined control sequence.
\rec-thy.sty-h@@k ... *{\req@nohref } \newtagform 
                                                  {colon}{}{:} \newenvironme...
l.3 \begin
          {document}
? ^[

Thanks in advance for looking at this. rec-thy is a great package that has saved me a lot of time, and I very much appreciate your work in having written it.

[beastaugh]

Managed to work around this by including the mathtools package before the rec-thy package. The following example compiles. Not sure what the underlying issue is.

\documentclass{article}
\usepackage{mathtools}
\usepackage{rec-thy}
\begin{document}
    Test.
\end{document}