Minor build/release fixups

Author: shesek

scripts/builder-osx.Dockerfile

@@ -4,7 +4,7 @@ ARG CROSSOSX_COMMIT=364703ca0962c4a12688daf8758802a5df9e3221
 ARG OSX_SDK_VERSION=10.11
 ARG OSX_SDK_SHASUM=694a66095a3514328e970b14978dc78c0f4d170e590fa7b2c3d3674b75f0b713
 
-RUN apt-get install -y git wget clang cmake libxml2-dev zlib1g-dev && \
+RUN apt-get update && apt-get install -y git wget clang cmake libxml2-dev zlib1g-dev && \
     rustup target add x86_64-apple-darwin
 
 RUN git clone https://github.com/tpoechtrager/osxcross /usr/src/osxcross && \

scripts/release.sh

@@ -36,6 +36,7 @@ cargo fmt -- --check
 if [ -z "$SKIP_BUILD" ]; then
   echo Building releases...
 
+  mkdir -p dist
   rm -rf dist/*
 
   if [ -z "$BUILD_HOST" ]; then
@@ -48,7 +49,7 @@ if [ -z "$SKIP_BUILD" ]; then
     fi
   else
     # macOS builds are disabled by default when building on the host.
-    # to enable, set TARGETS=linux,win,osx
+    # to enable, set TARGETS=x86_64-osx,...
     ./scripts/build.sh
   fi