diff --git a/README.md b/README.md
index a417c97..b717b8d 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ This repository contains configuration and driver code for running an end-to-end
 
 ## Quickstart
 
-This section provides a recipe for an end-to-end run of Nested EAGLE on Ursa.
+This section provides a recipe for an end-to-end run of Nested EAGLE on Ursa. GNU `make` version 3.82 or higher is required.
 
 In the `src/` directory:
 
@@ -19,7 +19,7 @@ In the `src/` directory:
 
 This step creates the runtime software environment, comprising conda virtual environments to support data prep, training, inference, and verification. The `conda/` subdirectory it creates is self-contained and can be removed and recreated by running the `make env` command again, as long as pipeline steps are not currently running.
 
-Developers who will be modifying Python driver code should replace `make env` with `make devenv`, which will create the same environments but also install additional code-quality tools for formatting, linting, shellchecking, typechecking, and unit testing.
+Developers who will be modifying Python driver code should replace `make env` with `make devenv`, which will create the same environments but also install additional code-quality tools for formatting, linting, shellchecking, typechecking, and YAML linting.
  
 **2. Run `make config compose=base:ursa >eagle.yaml` to create the EAGLE YAML config.**
 
@@ -256,9 +256,10 @@ After successful completion, the following `make` targets will be available:
 
 ``` bash
 make format     # format Python code
-make lint       # run the linter on Python code
-make shellcheck # run shellcheck on Bash scripts
-make typecheck  # run the typechecker on Python code
+make lint       # run a linter on Python code
+make shellcheck # run a checker on Bash scripts
+make typecheck  # run a typechecker on Python code
+make yamllint   # run a linter on YAML configs
 make test       # all of the above except formatting
 ```
 
diff --git a/src/Makefile b/src/Makefile
index 61d0fc0..839ee4f 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -3,7 +3,7 @@ ENVS     = data inference prewxvx training wxvx
 HELPERS  = prewxvx vx zarr
 PACKAGE  = eagle
 STEPS    = data grids-and-meshes inference prewxvx-global prewxvx-lam training vx-grid-global vx-grid-lam vx-obs-global vx-obs-lam zarr-gfs zarr-hrrr
-TOOLING  = config devenv env format lint realize shellcheck test typecheck validate
+TOOLING  = config devenv env format lint realize shellcheck test typecheck validate yamllint
 
 activate = @source conda/etc/profile.d/conda.sh && conda activate $(1)
 check    = @$(if $(1),,$(error $(2)= argument required))
@@ -98,7 +98,7 @@ shellcheck:
 	@echo "=> Checking shell scripts"
 	@(set -x && shellcheck --format=gcc --severity=info --shell=bash $(BASHSRCS))
 
-test: lint shellcheck typecheck
+test: lint shellcheck typecheck yamllint
 
 training:
 	$(call activate,training)
@@ -146,6 +146,11 @@ vx-obs-global:
 vx-obs-lam:
 	@$(make) vx truth=grid2obs extent=lam
 
+yamllint:
+	$(call activate,base)
+	@echo "=> Linting YAML configs"
+	@(set -x && yamllint --no-warnings config/)
+
 zarr:
 	$(call activate,data)
 ifeq ($(task),?)
diff --git a/src/config/base.yaml b/src/config/base.yaml
index 92e1939..5d96aba 100644
--- a/src/config/base.yaml
+++ b/src/config/base.yaml
@@ -1,5 +1,7 @@
 # This is the base EAGLE config. It currently configures the Nested EAGLE case.
 
+# yamllint disable rule:anchors rule:line-length
+
 app:
   base: /path/to/eagle/src
   experiment_name: default
diff --git a/src/config/ursa.yaml b/src/config/ursa.yaml
index e20f561..e53389d 100644
--- a/src/config/ursa.yaml
+++ b/src/config/ursa.yaml
@@ -1,5 +1,7 @@
 # Configuration for the NOAA RDHPCS Ursa platform.
 
+# yamllint disable rule:anchors rule:line-length
+
 app:
   gpu:
     batchargs: &gpu-batchargs
diff --git a/src/setup b/src/setup
index 6e7eb6d..da8e90d 100755
--- a/src/setup
+++ b/src/setup
@@ -1,18 +1,25 @@
 #!/usr/bin/env bash
 
-# shellcheck disable=1090,1091,2046,2048,2068,2086,2206,2155
+# shellcheck disable=1090,1091,2046,2048,2068,2086,2206,2207
 
-set -aeu
+set -aeuo pipefail
 
 INSTALLDIR=$PWD/conda
-MAKE="make=4.4.*"
 UWTOOLS="uwtools=2.13.*"
 
 # In all functions, make variables local unless they are either intended for global use, or set in
 # a subshell that exits at the end of the function.
 
+cachedir() {
+  (
+    conda_activate base
+    echo $CONDA_PREFIX/cache
+  )
+}
+
 conda_activate() {
-  local env=$1
+  local env
+  env=$1
   source $INSTALLDIR/etc/profile.d/conda.sh
   # Activation scripts shipped with conda packages may contain statements either expanding undefined
   # variables or exiting with error status, so temporarily disable the checks for these conditions,
@@ -23,13 +30,12 @@ conda_activate() {
 }
 
 conda_create() {
-  local name=$1
+  local name
+  name=$1
+  shift
   conda_activate base
   msg Creating environment: $name
-  # In each runtime virtual environment, "make format" requires jq to format JSON Schema files;
-  # invoking make targets requires make itself; and driver execution and config management require
-  # uwtools, so install those.
-  conda create -y -q -c ufs-community -n $* jq $MAKE $UWTOOLS
+  conda create -y -q -c ufs-community -n $name $* $UWTOOLS
   (
     # When runtime virtual environments are activated, set XDG_CACHE_HOME so that pip caches package
     # files in the runtime area, rather than in the user's home directory, which might impact their
@@ -41,7 +47,7 @@ conda_create() {
 if [[ -v XDG_CACHE_HOME ]]; then
   export EAGLE_OLD_XDG_CACHE_HOME=\$XDG_CACHE_HOME
 fi
-export XDG_CACHE_HOME=\$_CONDA_ROOT/cache
+export XDG_CACHE_HOME=$(cachedir)
 EOF
     dir_deactivate=$CONDA_PREFIX/etc/conda/deactivate.d
     mkdir -pv $dir_deactivate
@@ -56,86 +62,145 @@ EOF
 }
 
 conda_create_base() {
-  true
+  local name pkgs
+  name=base
+  pkgs=(
+    jq=1.8.*
+    shellcheck=0.11.*
+    $UWTOOLS
+    yamllint=1.38.*
+  )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  conda_install $name -c ufs-community ${pkgs[@]}
 }
 
 conda_create_data() {
-  local name=data
-  conda_env_exists $name && return || true
-  conda_create $name impi_rt=2021.13.* mpi4py=4.1.* numpy=1.26.4 pandas=2.3.3 types-pyyaml ufs2arco=0.18.*
-  (
-    conda_activate $name
-    dir_activate=$CONDA_PREFIX/etc/conda/activate.d
-    mkdir -pv $dir_activate
-    cat <<EOF >>$CONDA_PREFIX/etc/conda/activate.d/eagle.sh
+  local args name pkgs
+  name=data
+  pkgs=(
+    impi_rt=2021.13.*
+    mpi4py=4.1.*
+    numpy=1.26.4
+    pandas=2.3.3
+    types-pyyaml
+    ufs2arco=0.18.*
+  )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  args=( $name ${pkgs[@]} )
+  if conda_env_exists $name; then
+    conda_install ${args[@]}
+  else
+    conda_create ${args[@]}
+    (
+      conda_activate $name
+      dir_activate=$CONDA_PREFIX/etc/conda/activate.d
+      mkdir -pv $dir_activate
+      cat <<EOF >>$CONDA_PREFIX/etc/conda/activate.d/eagle.sh
 if [[ -v FI_PSM3_UUID ]]; then
   export EAGLE_OLD_FI_PSM3_UUID=\$FI_PSM3_UUID
 fi
 export FI_PSM3_UUID=eagle
 EOF
-    dir_deactivate=$CONDA_PREFIX/etc/conda/deactivate.d
-    mkdir -pv $dir_deactivate
-    cat <<EOF >>$CONDA_PREFIX/etc/conda/deactivate.d/eagle.sh
+      dir_deactivate=$CONDA_PREFIX/etc/conda/deactivate.d
+      mkdir -pv $dir_deactivate
+      cat <<EOF >>$CONDA_PREFIX/etc/conda/deactivate.d/eagle.sh
 unset FI_PSM3_UUID
 if [[ -v EAGLE_OLD_FI_PSM3_UUID ]]; then
   export FI_PSM3_UUID=\$EAGLE_OLD_FI_PSM3_UUID
   unset EAGLE_OLD_FI_PSM3_UUID
 fi
 EOF
-  )
+    )
+  fi
   pip_install $name anemoi-datasets==0.5.* anemoi-graphs==0.6.*
 }
 
 conda_create_inference() {
-  local name=inference
-  conda_env_exists $name && return || true
-  (
-    CONDA_OVERRIDE_CUDA=$(cuda_release) conda_create $name flash-attn=2.8.* numpy=2.2.6 python=3.12
-    conda_activate $name
-    write_anemoi_activation_scripts
+  local args name pkgs
+  name=inference
+  pkgs=(
+    flash-attn=2.8.*
+    numpy=2.2.6.*
+    python=3.12
   )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  args=( $name ${pkgs[@]} )
+  if conda_env_exists $name; then
+    conda_install ${args[@]}
+  else
+    conda_create ${args[@]}
+    write_anemoi_activation_scripts $name
+  fi
   pip_install $name anemoi-inference==0.7.* anemoi-models==0.9.* eagle-tools
 }
 
 conda_create_prewxvx() {
-  local name=prewxvx
-  conda_env_exists $name && return || true
-  conda_create $name python=3.13 xesmf
+  local args name pkgs
+  name=prewxvx
+  pkgs=(
+    numpy=2.2.6.*
+    pandas=2.3.3.*
+    python=3.13
+    xesmf=0.8.*
+  )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  args=( $name ${pkgs[@]} )
+  if conda_env_exists $name; then
+    conda_install ${args[@]}
+  else
+    conda_create ${args[@]}
+  fi
   pip_install $name eagle-tools
 }
 
 conda_create_training() {
-  local name=training
-  conda_env_exists $name && return || true
-  (
-    CONDA_OVERRIDE_CUDA=$(cuda_release) conda_create $name flash-attn=2.8.* numpy=1.26.4 python=3.12
-    conda_activate $name
-    write_anemoi_activation_scripts
+  local args name pkgs
+  name=training
+  pkgs=(
+    flash-attn=2.8.*
+    numpy=1.26.4.*
+    python=3.12
   )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  args=( $name ${pkgs[@]} )
+  if conda_env_exists $name; then
+    conda_install ${args[@]}
+  else
+    conda_create ${args[@]}
+    write_anemoi_activation_scripts $name
+  fi
   pip_install $name anemoi-models==0.9.* anemoi-training==0.6.*
 }
 
 conda_create_wxvx() {
-  local name=wxvx
-  conda_env_exists $name && return || true
-  conda_create $name -c oar-gsl wxvx=0.7.*
+  local args name pkgs
+  name=wxvx
+  pkgs=(
+    wxvx=0.7.*
+  )
+  test -v EAGLE_DEV && pkgs+=( $(devpkgs) )
+  args=( $name -c oar-gsl ${pkgs[@]} )
+  if conda_env_exists $name; then
+    conda_install ${args[@]}
+  else
+    conda_create ${args[@]}
+  fi
 }
 
 conda_env_exists() {
   name=$1
   (
     conda_activate base
-    if conda env list --json | jq -r .envs_details[].name | grep -q "^$name$"; then
-      msg Found existing conda environment: $name
-      exit 0
-    fi
-    exit 1
+    conda env list --json | jq -r .envs_details[].name | grep -q "^${name}$"
+    test $? -eq 0 && msg Found existing conda environment: $name
   )
 }
 
 conda_install() {
-  local name=$1
+  local name
+  name=$1
   shift
+  msg Installing conda packages into environment: $name
   (
     conda_activate $name
     set +eu
@@ -144,13 +209,6 @@ conda_install() {
   )
 }
 
-conda_install_devpkgs() {
-  local name=$1
-  local devpkgs=( $MAKE mypy=1.19.* ruff=0.14.* )
-  msg Installing dev packages into environment: $name
-  conda_install $name "${devpkgs[@]}"
-}
-
 cuda_command_file() {
   local path val
   val=${ARGS[cudascript]}
@@ -166,19 +224,27 @@ cuda_release() {
   )
 }
 
+devpkgs() {
+  local pkgs=(
+    mypy=1.19.*
+    ruff=0.14.*
+  )
+  echo ${pkgs[@]}
+}
+
 install_conda() {
+  local installer url ver
   if [[ -d $INSTALLDIR ]]; then
     msg Found existing conda installation: $INSTALLDIR
     return
   fi
-  local ver=25.9.1-0
-  local installer=Miniforge3-$ver-$(uname -s)-$(uname -p).sh
-  local url=https://github.com/conda-forge/miniforge/releases/download/$ver/$installer
+  ver=25.9.1-0
+  installer=Miniforge3-$ver-$(uname -s)-$(uname -p).sh
+  url=https://github.com/conda-forge/miniforge/releases/download/$ver/$installer
   msg Installing conda
   wget -nv $url
   bash $installer -bfp $INSTALLDIR
   rm -v $installer
-  conda_install base -c ufs-community $UWTOOLS
 }
 
 msg() {
@@ -188,7 +254,7 @@ msg() {
 parse_kvargs() {
   local arg key required val
   declare -g -A ARGS
-  for arg in "$@"; do
+  for arg in $@; do
     IFS="=" read -r key val <<< $arg
     ARGS[$key]=$val
   done
@@ -200,15 +266,20 @@ parse_kvargs() {
 }
 
 pip_install() {
-  local name=$1
+  local name
+  name=$1
   shift
+  msg Installing pip packages into environment: $name
   (
     conda_activate $name
-    pip install "$@"
+    pip install $@ | grep -v "^Requirement already satisfied: .*$"
   )
 }
 
 write_anemoi_activation_scripts() {
+  local name=$1
+  (
+    conda_activate $name
     cat <<EOF >>$CONDA_PREFIX/etc/conda/activate.d/eagle.sh
 modules="\$(module --terse list 2>/dev/null | grep -v 'No modules loaded' | tr '\n' ' ')"
 if [[ -n "\$modules" ]]; then
@@ -223,14 +294,16 @@ if [[ -v EAGLE_OLD_MODULES ]]; then
   unset EAGLE_OLD_MODULES
 fi
 EOF
+  )
 }
 
 parse_kvargs $@
 install_conda
-conda_install base shellcheck $UWTOOLS
+CONDA_OVERRIDE_CUDA=$(cuda_release)
+XDG_CACHE_HOME=$(cachedir)
+export CONDA_OVERRIDE_CUDA XDG_CACHE_HOME
 environments=( base data inference prewxvx training wxvx )
-for name in ${environments[*]}; do
+for name in ${environments[@]}; do
   conda_create_$name
-  test -v EAGLE_DEV && conda_install_devpkgs $name
 done
 msg Done