chore: address review feedback -set e -set u + dx docs

DEVELOPER.md

@@ -9,6 +9,6 @@ npm test
 ```
 
 
-_notes_ - As a developer you need you download the FFI libraries prior to running `npm install` / `npm ci` as the libraries will be expected to be there, and you won't have any `node_modules` installed yet.
+_notes_ - As a developer, you need to run `bash script/download-libs.sh` to download the FFI libraries prior to running `npm install` / `npm ci` as the libraries will be expected to be there, and you won't have any `node_modules` installed yet.
 
 For end users, the `ffi` folder is populated, as part of the npm publishing step.

script/ci/build-and-test.sh

@@ -1,5 +1,6 @@
 #!/bin/bash -eu
-set -eu # This needs to be here for windows bash, which doesn't read the #! line above
+set -e # This needs to be here for windows bash, which doesn't read the #! line above
+set -u
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")"; pwd)" # Figure out where the script is running
 . "$SCRIPT_DIR"/../lib/robust-bash.sh