diff --git a/users/pbsds/home/profiles/bashrc.d/nix-shell.sh b/users/pbsds/home/profiles/bashrc.d/nix-shell.sh
index 690894f..7191e48 100644
--- a/users/pbsds/home/profiles/bashrc.d/nix-shell.sh
+++ b/users/pbsds/home/profiles/bashrc.d/nix-shell.sh
@@ -1,11 +1,11 @@
 _ns() {
   local is_dev=$1; shift # "true" or "false"
-  local args=()
   if $is_dev; then
     local arg_suffix="^*"
   else
     local arg_suffix=""
   fi
+  local args=()
   for pkg in "$@"; do
     if [[ "$pkg" = -- ]]; then
       break
@@ -19,13 +19,13 @@ _ns() {
 
   # Run anything after -- as a command
   local cmd=("$@")
-  while [[ "${#cmd[@]}" -gt 2 && ${cmd[0]} != "--" ]]; do
+  while [[ "${#cmd[@]}" -gt 1 && "${cmd[0]}" != "--" ]]; do
     cmd=("${cmd[@]:1}")
   done
   cmd=("${cmd[@]:1}")
   if [[ ${#cmd[@]} -gt 0 ]]; then
     (
-      _ns false "$args"
+      _ns false "${args[@]}"
       set -x
       "${cmd[@]}"
     )
@@ -52,6 +52,7 @@ _ns() {
   readarray -d $'\n' -t storepaths_build  <<<"$outpaths"
 
   # traverse propagated inputs
+  # this is safe since the store paths form a DAG
   # TODO: rethink this logic
   local -i idx=-1
   while [[ $((++idx)) -lt "${#storepaths_native[@]}" ]]; do
@@ -77,42 +78,42 @@ _ns() {
   local -a add_to_include=()
   local -a add_to_pythonpath=()
 
+  local -A seen=()
   # for storepath in "${storepaths_native[@]}"; do
   for storepath in "${storepaths_build[@]}"; do
+    if [[ -n "${seen["$storepath"]:-}" ]]; then
+      continue
+    fi
+    seen["$storepath"]=1
+
     if [[ -d "$storepath/bin" ]]; then
-      add_to_path+=("$storepath/bin")
+      export PATH="$storepath/bin${PATH:+":$PATH"}"
     fi
     if >/dev/null compgen -G "$storepath/lib/*.so"; then
-      add_to_libs+=("$storepath"/lib/*.so)
+      export LD_LIBRARY_PATH="$(IFS=: ; printf "%s" "$storepath"/lib/*.so)${LD_LIBRARY_PATH:+":$LD_LIBRARY_PATH"}"
     fi
     if >/dev/null compgen -G "$storepath/lib/*.so.*"; then
-      add_to_libs+=("$storepath"/lib/*.so.*)
+      export LD_LIBRARY_PATH="$(IFS=: ; printf "%s" "$storepath"/lib/*.so.*)${LD_LIBRARY_PATH:+":$LD_LIBRARY_PATH"}"
+      export CMAKE_LIBRARY_PATH="$storepath/lib${CMAKE_LIBRARY_PATH:+":$CMAKE_LIBRARY_PATH"}"
+    fi
+    if [[ -d "$storepath/lib/pkgconfig" ]]; then
+      export PKG_CONFIG_PATH="$storepath/lib/pkgconfig${PKG_CONFIG_PATH:+":$PKG_CONFIG_PATH"}"
     fi
     if [[ -d "$storepath/share" ]]; then
-      add_to_share+=("$storepath/share")
+      export XDG_DATA_DIRS="$storepath/share${XDG_DATA_DIRS:+":$XDG_DATA_DIRS"}"
+    fi
+    if [[ -d "$storepath/share/pkgconfig" ]]; then
+      export PKG_CONFIG_PATH="$storepath/share/pkgconfig${PKG_CONFIG_PATH:+":$PKG_CONFIG_PATH"}"
+    fi
+    if [[ -d "$storepath/include" ]]; then
+      export CPATH="$storepath/include${CPATH:+":$CPATH"}"
+      export CMAKE_INCLUDE_PATH="$storepath/include${CMAKE_INCLUDE_PATH:+":$CMAKE_INCLUDE_PATH"}"
     fi
     if >/dev/null compgen -G "$storepath/lib/python*/site-packages"; then
-      add_to_pythonpath+=("$storepath"/lib/python*/site-packages)
+      export PYTHONPATH="$(IFS=: ; printf "%s" "$storepath"/lib/python*/site-packages)${PYTHONPATH:+":$PYTHONPATH"}"
+      # export PYTHONNOUSERSITE=1
     fi
   done
-
-  if [[ "${#add_to_path[@]}" -gt 0 ]]; then
-    export PATH="$(IFS=: ; printf "%s" "${add_to_path[*]}")${PATH:+":$PATH"}"
-  fi
-  if [[ "${#add_to_libs[@]}" -gt 0 ]]; then
-    export LD_LIBRARY_PATH="$(IFS=: ; printf "%s" "${add_to_libs[*]}")${LD_LIBRARY_PATH:+":$LD_LIBRARY_PATH"}"
-  fi
-  if [[ "${#add_to_share[@]}" -gt 0 ]]; then
-    export XDG_DATA_DIRS="$(IFS=: ; printf "%s" "${add_to_share[*]}")${XDG_DATA_DIRS:+":$XDG_DATA_DIRS"}"
-  fi
-  if [[ "${#add_to_include[@]}" -gt 0 ]]; then
-    export CPATH="$(IFS=: ; printf "%s" "${add_to_include[*]}")${CPATH:+":$CPATH"}"
-    export CMAKE_INCLUDE_PATH="$(IFS=: ; printf "%s" "${add_to_include[*]}")${CMAKE_INCLUDE_PATH:+":$CMAKE_INCLUDE_PATH"}"
-  fi
-  if [[ "${#add_to_pythonpath[@]}" -gt 0 ]]; then
-    export PYTHONPATH="$(IFS=: ; printf "%s" "${add_to_pythonpath[*]}")${PYTHONPATH:+":$PYTHONPATH"}"
-    # export PYTHONNOUSERSITE=1
-  fi
 }
 
 ns() { _ns false "$@"; }