🐛 ocrd_olena: Fail the build if scribo-cli is borken

Dockerfile-ocrd_olena

@@ -11,12 +11,15 @@ RUN apt-get update && \
       imagemagick \
     && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
+
+# Install olena from .deb
 RUN curl -sSL --retry 3 -O https://qurator-data.de/~mike.gerber/olena_2.1-0+ocrd-git/olena-bin_2.1-0+ocrd-git_amd64.deb && \
     dpkg -i --force-depends olena-bin_2.1-0+ocrd-git_amd64.deb && \
     rm -f olena-bin_2.1-0+ocrd-git_amd64.deb && \
     apt-get update && \
     apt-get -f install -y && \
-    apt-get clean && rm -rf /var/lib/apt/lists/*
+    apt-get clean && rm -rf /var/lib/apt/lists/* && \
+    if ! scribo-cli sauvola --help >/dev/null 2>&1; then echo "Olena/scribo is not installed correctly" >&2; exit 1; fi
 RUN curl -sSL --retry 3 -o ocrd_olena.tar.gz https://github.com/OCR-D/ocrd_olena/archive/v${OCRD_OLENA_VERSION}.tar.gz && \
    mkdir ocrd_olena && \
    tar xvz -C ocrd_olena --strip-components=1 -f ocrd_olena.tar.gz && \