On macOS, jtreg fails to compile because sed can't compile a regular expression:

/bin/mkdir -p /Users/.../dev/ojdk/jdktools/jtreg/build/images/jtreg/doc/jtreg
/opt/local/bin/pandoc \
            --standalone \
            --include-in-header ../src/share/doc/javatest/regtest/faq-local-style.html \
            --include-before ../src/share/doc/javatest/regtest/faq-intro.html \
            --toc \
            --to html5 \
            --number-sections \
            ../src/share/doc/javatest/regtest/faq.md | \
        /usr/bin/sed \
            -e 's/^code > span\.\([a-z][a-z] .*\)/code span.\1/' \
            -e 's/-section-number">0./-section-number">/' \
            -e 's/.../\…/g' \
            -e 's/™/\™/g' \
            -e '/<header>/{:a;N;/<\/header>/!ba};/<h1 class="title">/d' \
            > /Users/.../dev/ojdk/jdktools/jtreg/build/images/jtreg/doc/jtreg/faq.html
sed: 2: "/<header>/{:a;N;/<\/hea ...": unexpected EOF (pending }'s)
make: *** [/Users/.../dev/ojdk/jdktools/jtreg/build/images/jtreg/doc/jtreg/faq.html] Error 1
jstcloud1:jtreg $