fix docker build and related documentation

2 files changed, 2 insertions, 1 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index deee1b60d..6de52e863 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -130,7 +130,7 @@ If you want to copy them outside of the image, simply mount a volume into a diff
 ```bash
 DATE=`date +"%Y-%b-%d-%H-%M"`
 mkdir -p ~/Downloads/$DATE
-docker run -e GIT_SHA=`git rev-parse --short HEAD` -v ~/Downloads/$DATE:/ferdium-out -it ferdium-package sh
+docker run -e GIT_SHA=`git rev-parse --short HEAD` -v ~/Downloads/$DATE:/ferdium-out -it ferdium-package-`uname -m` sh
 # inside the container:
 mv /ferdium/Ferdium-*.AppImage /ferdium-out/Ferdium-$GIT_SHA.AppImage
 mv /ferdium/ferdium-*.tar.gz /ferdium-out/Ferdium-$GIT_SHA.tar.gz
diff --git a/Dockerfile b/Dockerfile
index 0b1d3bccb..83baba00b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,6 +13,7 @@ ARG PREVAL_BUILD_INFO_PLACEHOLDERS=true
 # Note: 'fpm' is needed for building on ARM machines
 RUN apt-get update -y \
   && apt-get install --no-install-recommends -y rpm ruby gem \
+  && gem install dotenv -v 2.8.1 --no-ri --no-rdoc --no-document \
   && gem install fpm --no-ri --no-rdoc --no-document
 
 WORKDIR /usr/src/ferdium