By bisecting makefile I've found the problematic line: MARKDOWN_FILES := $(wildcard transcriptions/*.md)
Removing it make things work. ls is working fine with the given wildcard: $ ls transcriptions/*.md transcriptions/[155-,_it]_Giovannino_e_Il_Lanzino_e_Il_Papa_-_Manuscritto_di_baletti.md transcriptions/[1589,_it]_Prospero_Luti_-_Opera_bellissima_di_gagliarda.md transcriptions/[1706,_uk]_Raoul-Auger_Feuillet_-_Orchesography_or_the_Art_of_Dancing.md transcriptions/[1749,_sc]_The_Register_of_Dances_at_Castle_Menzies.md transcriptions/[1819,_fr]_J._H._Gourdoux-Daux_-_Requeil_de_genre_nouveau_de_contredanses_et_walses.md transcriptions/[1824,_uk]_Thomas_Wilson_-_Danciad.md transcriptions/[1825,_ru]_Людовик_Петровский_-_Правила_для_благородных_общественных_танцев.md transcriptions/[1828,_ru]_Собрание_фигур_для_котильона.md transcriptions/[183-,_uk]_Thomas_Wilson_-_The_Fashionable_Quadrille_Preceptor.md transcriptions/[1902,_ru]_Николай_Людвигович_Гавликовский_-_Руководство_для_изучения_танцев,_édition_2.md
