Dockerfile convention.

Author: ludgerpaehler

.packaging/Dockerfile.cpp_env

@@ -61,4 +61,4 @@ RUN apt-get autoremove -y --purge \
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/*
 
-ENV DEBIAN_FRONTEND=
+ENV DEBIAN_FRONTEND=

.packaging/Dockerfile.julia_env

@@ -58,4 +58,4 @@ RUN apt-get autoremove -y --purge \
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/*
 
-ENV DEBIAN_FRONTEND=
+ENV DEBIAN_FRONTEND=

.packaging/Dockerfile.rust_env

@@ -51,4 +51,4 @@ RUN apt-get autoremove -y --purge \
 && apt-get clean -y \
 && rm -rf /var/lib/apt/lists/*
 
-ENV DEBIAN_FRONTEND=
+ENV DEBIAN_FRONTEND=

.packaging/Dockerfile.swift_env

@@ -60,4 +60,4 @@ RUN apt-get autoremove -y --purge \
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/*
 
-ENV DEBIAN_FRONTEND=
+ENV DEBIAN_FRONTEND=