diff --git a/.architectures-lib b/.architectures-lib
index 724a716..8d384fa 100644
--- a/.architectures-lib
+++ b/.architectures-lib
@@ -17,6 +17,12 @@ hasBashbrewArch() {
 	_awkArch "$version" 'BEGIN { exitCode = 1 } $1 == bashbrewArch { exitCode = 0 } END { exit exitCode }' -v bashbrewArch="$bashbrewArch"
 }
 
+dpkgToBashbrewArch() {
+	local version="$1"; shift
+	local dpkgArch="$1"; shift
+	_awkArch "$version" '$2 == dpkgArch { print $1; exit }' -v dpkgArch="$dpkgArch"
+}
+
 dpkgToJuliaTarArch() {
 	local version="$1"; shift
 	local dpkgArch="$1"; shift
diff --git a/generate-stackbrew-library.sh b/generate-stackbrew-library.sh
index dbfe362..8498e61 100755
--- a/generate-stackbrew-library.sh
+++ b/generate-stackbrew-library.sh
@@ -55,7 +55,7 @@ parentArches() {
 
 	local arches=()
 	for arch in $parentArches; do
-		if hasBashbrewArch "$version" "$arch"; then
+		if hasBashbrewArch "$version" "$arch" && grep -qE "^# $arch\$" "$dir/Dockerfile"; then
 			arches+=( "$arch" )
 		fi
 	done
diff --git a/jessie/Dockerfile b/jessie/Dockerfile
index 7eda9d2..47a393a 100644
--- a/jessie/Dockerfile
+++ b/jessie/Dockerfile
@@ -17,7 +17,7 @@ ENV PATH $JULIA_PATH/bin:$PATH
 ENV JULIA_GPG 3673DF529D9049477F76B37566E3C7DC03D6E495
 
 # https://julialang.org/downloads/
-ENV JULIA_VERSION 0.6.3
+ENV JULIA_VERSION 0.6.4
 
 RUN set -eux; \
 	\
@@ -32,14 +32,14 @@ RUN set -eux; \
 	fi; \
 	\
 # https://julialang.org/downloads/#julia-command-line-version
-# https://julialang-s3.julialang.org/bin/checksums/julia-0.6.3.sha256
+# https://julialang-s3.julialang.org/bin/checksums/julia-0.6.4.sha256
 # this "case" statement is generated via "update.sh"
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "${dpkgArch##*-}" in \
-		amd64) tarArch='x86_64'; dirArch='x64'; sha256='36212ed8e1c864599e9f149d884d504eee15b57b96bf918cb5b9ac35a5ab6283' ;; \
-		armhf) tarArch='armv7l'; dirArch='armv7l'; sha256='abe9dd0cbf890a13bfe69581bf4eee100c8834bf4c0296416d20af54d80e6d9a' ;; \
-		arm64) tarArch='aarch64'; dirArch='aarch64'; sha256='cdd1420fc3df0058978ccb20e2f4db47cb6d3dd164cb67ba70ee2d5c99306c47' ;; \
-		i386) tarArch='i686'; dirArch='x86'; sha256='3e6f2c3d0a168077ddd61383566513303b0153c56352df2dde1531eb16d79143' ;; \
+# amd64
+		amd64) tarArch='x86_64'; dirArch='x64'; sha256='d20e6984bcf8c3692d853a9922e2cf1de19b91201cb9e396d9264c32cebedc46' ;; \
+# i386
+		i386) tarArch='i686'; dirArch='x86'; sha256='ab45280c799e63ab04da7a928fee79b43e41b457a6d4c48058798b9bad542688' ;; \
 		*) echo >&2 "error: current architecture ($dpkgArch) does not have a corresponding Julia binary release"; exit 1 ;; \
 	esac; \
 	\
diff --git a/release-architectures b/release-architectures
index 08feb9d..8775207 100644
--- a/release-architectures
+++ b/release-architectures
@@ -5,6 +5,4 @@ amd64   amd64   x86_64  x64
 arm32v7 armhf   armv7l  armv7l
 arm64v8 arm64   aarch64 aarch64
 i386    i386    i686    x86
-
-# ppc64le appears to be "0.6.0-rc3"-only as of 2017-08-24
-#ppc64le ppc64el ppc64le ppc64le
+ppc64le ppc64el ppc64le ppc64le
diff --git a/stretch/Dockerfile b/stretch/Dockerfile
index 61f4ef8..6a7b5b5 100644
--- a/stretch/Dockerfile
+++ b/stretch/Dockerfile
@@ -17,7 +17,7 @@ ENV PATH $JULIA_PATH/bin:$PATH
 ENV JULIA_GPG 3673DF529D9049477F76B37566E3C7DC03D6E495
 
 # https://julialang.org/downloads/
-ENV JULIA_VERSION 0.6.3
+ENV JULIA_VERSION 0.6.4
 
 RUN set -eux; \
 	\
@@ -32,14 +32,14 @@ RUN set -eux; \
 	fi; \
 	\
 # https://julialang.org/downloads/#julia-command-line-version
-# https://julialang-s3.julialang.org/bin/checksums/julia-0.6.3.sha256
+# https://julialang-s3.julialang.org/bin/checksums/julia-0.6.4.sha256
 # this "case" statement is generated via "update.sh"
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "${dpkgArch##*-}" in \
-		amd64) tarArch='x86_64'; dirArch='x64'; sha256='36212ed8e1c864599e9f149d884d504eee15b57b96bf918cb5b9ac35a5ab6283' ;; \
-		armhf) tarArch='armv7l'; dirArch='armv7l'; sha256='abe9dd0cbf890a13bfe69581bf4eee100c8834bf4c0296416d20af54d80e6d9a' ;; \
-		arm64) tarArch='aarch64'; dirArch='aarch64'; sha256='cdd1420fc3df0058978ccb20e2f4db47cb6d3dd164cb67ba70ee2d5c99306c47' ;; \
-		i386) tarArch='i686'; dirArch='x86'; sha256='3e6f2c3d0a168077ddd61383566513303b0153c56352df2dde1531eb16d79143' ;; \
+# amd64
+		amd64) tarArch='x86_64'; dirArch='x64'; sha256='d20e6984bcf8c3692d853a9922e2cf1de19b91201cb9e396d9264c32cebedc46' ;; \
+# i386
+		i386) tarArch='i686'; dirArch='x86'; sha256='ab45280c799e63ab04da7a928fee79b43e41b457a6d4c48058798b9bad542688' ;; \
 		*) echo >&2 "error: current architecture ($dpkgArch) does not have a corresponding Julia binary release"; exit 1 ;; \
 	esac; \
 	\
diff --git a/update.sh b/update.sh
index 5c6366e..bb31bdc 100755
--- a/update.sh
+++ b/update.sh
@@ -27,11 +27,13 @@ for version in '.'; do
 	for dpkgArch in $(dpkgArches "$version"); do
 		tarArch="$(dpkgToJuliaTarArch "$version" "$dpkgArch")"
 		dirArch="$(dpkgToJuliaDirArch "$version" "$dpkgArch")"
-		sha256="$(echo "$sha256s" | grep "julia-${fullVersion}-linux-${tarArch}.tar.gz$" | cut -d' ' -f1)"
+		sha256="$(echo "$sha256s" | grep "julia-${fullVersion}-linux-${tarArch}.tar.gz$" | cut -d' ' -f1 || :)"
 		if [ -z "$sha256" ]; then
-			echo >&2 "error: cannot find sha256 for $fullVersion on arch $tarArch / $dirArch ($dpkgArch)"
-			exit 1
+			echo >&2 "warning: cannot find sha256 for $fullVersion on arch $tarArch / $dirArch ($dpkgArch); skipping"
+			continue
 		fi
+		bashbrewArch="$(dpkgToBashbrewArch "$version" "$dpkgArch")"
+		linuxArchCase+="# $bashbrewArch"$'\n'
 		linuxArchCase+=$'\t\t'"$dpkgArch) tarArch='$tarArch'; dirArch='$dirArch'; sha256='$sha256' ;; "$'\\\n'
 	done
 	linuxArchCase+=$'\t\t''*) echo >&2 "error: current architecture ($dpkgArch) does not have a corresponding Julia binary release"; exit 1 ;; '$'\\\n'
diff --git a/windows/windowsservercore-1709/Dockerfile b/windows/windowsservercore-1709/Dockerfile
index d793e33..8ae71d7 100644
--- a/windows/windowsservercore-1709/Dockerfile
+++ b/windows/windowsservercore-1709/Dockerfile
@@ -3,8 +3,8 @@ FROM microsoft/windowsservercore:1709
 # $ProgressPreference: https://github.com/PowerShell/PowerShell/issues/2138#issuecomment-251261324
 SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
 
-ENV JULIA_VERSION 0.6.3
-ENV JULIA_SHA256 e6eef263bbe6d95d2def300407edb6a624e77166d73f423cd7fc895f8464cffd
+ENV JULIA_VERSION 0.6.4
+ENV JULIA_SHA256 aa16b5fb54ab2821a09022db83d92db5d07c1092a24b7091f54fb4bca9e564eb
 
 RUN $url = ('https://julialang-s3.julialang.org/bin/winnt/x64/{1}/julia-{0}-win64.exe' -f $env:JULIA_VERSION, ($env:JULIA_VERSION -replace '[.-][^.-]+$', '')); \
         Write-Host ('Downloading {0} ...' -f $url); \
diff --git a/windows/windowsservercore-ltsc2016/Dockerfile b/windows/windowsservercore-ltsc2016/Dockerfile
index 7f565e2..84a0d89 100644
--- a/windows/windowsservercore-ltsc2016/Dockerfile
+++ b/windows/windowsservercore-ltsc2016/Dockerfile
@@ -3,8 +3,8 @@ FROM microsoft/windowsservercore:ltsc2016
 # $ProgressPreference: https://github.com/PowerShell/PowerShell/issues/2138#issuecomment-251261324
 SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
 
-ENV JULIA_VERSION 0.6.3
-ENV JULIA_SHA256 e6eef263bbe6d95d2def300407edb6a624e77166d73f423cd7fc895f8464cffd
+ENV JULIA_VERSION 0.6.4
+ENV JULIA_SHA256 aa16b5fb54ab2821a09022db83d92db5d07c1092a24b7091f54fb4bca9e564eb
 
 RUN $url = ('https://julialang-s3.julialang.org/bin/winnt/x64/{1}/julia-{0}-win64.exe' -f $env:JULIA_VERSION, ($env:JULIA_VERSION -replace '[.-][^.-]+$', '')); \
         Write-Host ('Downloading {0} ...' -f $url); \