Add regex-pcre2 to the Debian Testing image

libghc-regex-pcre2-dev is now available in Debian testing and work is
underway to support it in Ganeti as well. Add it to the Debian testing
image to be able to test building against it.

Signed-off-by: Apollon Oikonomopoulos <[email protected]>

Author: apoikos

ganeti/Dockerfile.debian-testing

@@ -28,6 +28,7 @@ RUN apt-get update && apt-get install --yes --no-install-recommends \
   libghc-hinotify-dev \
   libghc-base64-bytestring-dev \
   libghc-zlib-dev \
+  libghc-regex-pcre2-dev \
   libghc-regex-tdfa-dev \
   libghc-attoparsec-dev \
   libghc-vector-dev \