diff --git a/build-ci.sh b/build-ci.sh
new file mode 100755
index 0000000..d0719f1
--- /dev/null
+++ b/build-ci.sh
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+# first arg is $BUILD_LANG, currently supported:
+# 1. rust, this runs $BUILD_SCRIPT with env variable TARGET and DISABLE_TESTS set appropriately once for each target supported by cross
+#    this'll have to do until cross can run in docker containers backed by the btrfs driver...
+# 2. c, this runs $BUILD_SCRIPT inside an alpine linux container, once for each ARCH supported by build.sh here
+
+# run like (for rust):
+#   curl --compressed -sL https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/build-ci.sh | bash -s -- rust
+#   curl --compressed -sL https://raw.githubusercontent.com/moparisthebest/self-ci/master/build-ci.sh | sed 's@https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master@https://raw.githubusercontent.com/moparisthebest/self-ci/master@g' | bash -s -- rust
+
+export BUILD_LANG="${1-rust}"
+shift
+export BUILD_SCRIPT="${1-.jenkins/build.sh}"
+shift
+export RELEASE_SCRIPT="${1-.jenkins/release.sh}"
+shift
+
+set -euxo pipefail
+
+mkdir -p bin
+cd bin
+curl --compressed -sL -O 'https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/ci-release-helper.sh' -O "https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/$BUILD_LANG/build.sh"
+chmod +x ci-release-helper.sh build.sh
+cd ..
+export PATH="$(pwd)/bin:$PATH"
+
+build.sh "$BUILD_SCRIPT" "$@"
+
+if [ -e "$RELEASE_SCRIPT" ]
+then
+    "$RELEASE_SCRIPT" "$@"
+elif [ -d 'release' ]
+then
+    # default release script
+    ci-release-helper.sh standard_pre_release
+    cd release
+    find -type f ! -path ./sha256sum.txt -print0 | xargs -0 sha256sum > sha256sum.txt
+    gpg --clearsign sha256sum.txt
+    ci-release-helper.sh standard_multi_release 'sha256sum.txt' 'text/plain'
+    ci-release-helper.sh standard_multi_release 'sha256sum.txt.asc' 'text/plain'
+    rm -f sha256sum.txt sha256sum.txt.asc
+    find -type f -print0 | xargs -0n1 -I {} ci-release-helper.sh standard_multi_release '{}' 'application/octet-stream'
+fi
+
+exit 0
diff --git a/c/build.sh b/c/build.sh
new file mode 100755
index 0000000..e7aec01
--- /dev/null
+++ b/c/build.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+set -euxo pipefail
+
+export BUILD_SCRIPT="${1-.jenkins/build.sh}"
+
+docker_build() {
+    export ARCH="$1"
+    shift
+    DOCKER_IMAGE="$1"
+
+    # run it, but after, chown anything left in /tmp to *this* uid/gid, otherwise we can't delete them later...
+    docker run --rm -e ARCH -v "$(pwd)":/tmp "$DOCKER_IMAGE" sh -c "'/tmp/$BUILD_SCRIPT'; exit=\$?; chown -R '$UID:$(id -g)' /tmp; exit \$exit"
+}
+
+docker_build 'amd64'   'alpine'
+
+# before first multiarch image, must register binfmt handlers
+docker run --rm --privileged multiarch/qemu-user-static:register --reset
+
+docker_build 'i386'    'multiarch/alpine:i386-latest-stable'
+docker_build 'aarch64' 'multiarch/alpine:aarch64-latest-stable'
+docker_build 'armv7'   'multiarch/alpine:armv7-latest-stable'
+docker_build 'ppc64le' 'multiarch/alpine:ppc64le-latest-stable'
diff --git a/rust/build-jenkins.sh b/rust/build-jenkins.sh
index fe6a846..ec7106b 100755
--- a/rust/build-jenkins.sh
+++ b/rust/build-jenkins.sh
@@ -1,14 +1,37 @@
 #!/bin/bash
 set -euxo pipefail
 
-# this'll have to do until cross can run in docker containers backed by the btrfs driver
-# run like: curl https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/rust/build-jenkins.sh | bash
+# this runs first arg or .jenkins/build.sh with env variable TARGET and DISABLE_TESTS set appropriately once for each target supported by cross
+# this'll have to do until cross can run in docker containers backed by the btrfs driver...
+
+# run like:
+#   curl --compressed -sL https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/rust/build-jenkins.sh | bash
+#   curl --compressed -sL https://raw.githubusercontent.com/moparisthebest/self-ci/master/rust/build-jenkins.sh | sed 's@https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master@https://raw.githubusercontent.com/moparisthebest/self-ci/master@g' | bash
+# or with custom script:
+#   curl --compressed -sL https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/rust/build-jenkins.sh | bash -s -- ./path/to/build.sh
+#   curl --compressed -sL https://raw.githubusercontent.com/moparisthebest/self-ci/master/rust/build-jenkins.sh | sed 's@https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master@https://raw.githubusercontent.com/moparisthebest/self-ci/master@g' | bash -s -- ./path/to/build.sh
+
+export BUILD_SCRIPT="${1-.jenkins/build.sh}"
+shift
+export RELEASE_SCRIPT="${1-.jenkins/release.sh}"
 
 mkdir bin
 cd bin
-curl -O https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/ci-release-helper.sh -O https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/rust/build.sh
+curl --compressed -sL -O https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/ci-release-helper.sh -O https://code.moparisthebest.com/moparisthebest/self-ci/raw/branch/master/rust/build.sh
 chmod +x ci-release-helper.sh build.sh
 cd ..
 export PATH="$(pwd)/bin:$PATH"
-ci-release-helper.sh standard_pre_release
-exec build.sh .jenkins/build.sh
+
+build.sh "$BUILD_SCRIPT"
+
+if [ -e "$RELEASE_SCRIPT" ]
+then
+    "$RELEASE_SCRIPT"
+elif [ -d 'release' ]
+then
+    # default release script
+    ci-release-helper.sh standard_pre_release
+    find release/ -type f -print0 | xargs -0n1 -I {} ci-release-helper.sh standard_multi_release '{}' 'application/octet-stream'
+fi
+
+exit 0
diff --git a/rust/build.sh b/rust/build.sh
index 12802c5..ca16a6b 100755
--- a/rust/build.sh
+++ b/rust/build.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 set -euo pipefail
 
+export CROSS_VERSION=0.2.1
+
 for TARGET in ${BUILD_TARGETS:-x86_64-unknown-linux-musl x86_64-unknown-linux-gnu i686-unknown-linux-musl i686-unknown-linux-gnu i586-unknown-linux-musl i586-unknown-linux-gnu aarch64-unknown-linux-musl aarch64-unknown-linux-gnu armv7-unknown-linux-gnueabihf armv7-unknown-linux-musleabihf arm-unknown-linux-gnueabi arm-unknown-linux-gnueabihf arm-unknown-linux-musleabi arm-unknown-linux-musleabihf armv5te-unknown-linux-gnueabi armv5te-unknown-linux-musleabi x86_64-pc-windows-gnu x86_64-linux-android i686-linux-android aarch64-linux-android armv7-linux-androideabi arm-linux-androideabi mips64el-unknown-linux-gnuabi64 mips64-unknown-linux-gnuabi64 mipsel-unknown-linux-gnu mipsel-unknown-linux-musl mips-unknown-linux-gnu mips-unknown-linux-musl powerpc64le-unknown-linux-gnu powerpc-unknown-linux-gnu riscv64gc-unknown-linux-gnu s390x-unknown-linux-gnu x86_64-sun-solaris sparcv9-sun-solaris x86_64-unknown-netbsd}
 do
     if echo "$TARGET" | grep -E '(^s390x|^thumb|solaris$|^x86_64-unknown-dragonfly$|^x86_64-unknown-netbsd$)' >/dev/null