way too overcomplicated!

users/pbsds/home/profiles/bashrc.d/nix-shell.sh

@@ -1,16 +1,83 @@
 function ns() {
-  args=()
-  for pkg in $@; do
+  local args=()
+  for pkg in "$@"; do
     args+=(nixpkgs#"$pkg")
   done
   >&2 echo + exec nix shell "${args[@]}"
-  local tmp=$(
+  local outpaths="$(
     export NIXPKGS_ALLOW_BROKEN
     export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM
     export NIXPKGS_ALLOW_UNFREE
     export NIXPKGS_ALLOW_INSECURE
-    nix --extra-experimental-features "nix-command flakes" shell --impure "${args[@]}" -c sh -c 'echo $PATH'
-  )
-  [[ $? -eq 0 && -n "$tmp" ]] || return 1
-  export PATH="$tmp"
+    nix --extra-experimental-features "nix-command flakes" build --impure "${args[@]}" --print-out-paths --no-link
+  )"
+  if [[ $? -ne 0 || -z "$outpaths" ]]; then
+    return
+  fi
+
+  local -a storepaths_native=()
+  local -a storepaths_build=()
+  readarray -d $'\n' -t storepaths_native <<<"$outpaths"
+  readarray -d $'\n' -t storepaths_build  <<<"$outpaths"
+
+  # traverse propagated inputs
+  local -i idx=-1
+  while [[ $((++idx)) -lt "${#storepaths_native[@]}" ]]; do
+    if [[ -f "${storepaths_native[$idx]}"/nix-support/propagated-native-build-inputs ]]; then
+      storepaths_native+=($(cat "${storepaths_native[$idx]}"/nix-support/propagated-native-build-inputs))
+    fi
+    if [[ -f "${storepaths_native[$idx]}"/nix-support/propagated-build-inputs ]]; then
+      storepaths_build+=($(cat "${storepaths_native[$idx]}"/nix-support/propagated-build-inputs))
+    fi
+  done
+  local -i idx=-1
+  while [[ $((++idx)) -lt "${#storepaths_build[@]}" ]]; do
+    if [[ -f "${storepaths_build[$idx]}"/nix-support/propagated-build-inputs ]]; then
+      storepaths_build+=($(cat "${storepaths_build[$idx]}"/nix-support/propagated-build-inputs))
+    fi
+  done
+
+  # find things to add to env
+  local -a add_to_path=()
+  local -a add_to_libs=()
+  local -a add_to_share=()
+  local -a add_to_include=()
+  local -a add_to_pythonpath=()
+
+  # for storepath in "${storepaths_native[@]}"; do
+  for storepath in "${storepaths_build[@]}"; do
+    if [[ -d "$storepath/bin" ]]; then
+      add_to_path+=("$storepath/bin")
+    fi
+    if >/dev/null compgen -G "$storepath/lib/*.so"; then
+      add_to_libs+=("$storepath"/lib/*.so)
+    fi
+    if >/dev/null compgen -G "$storepath/lib/*.so.*"; then
+      add_to_libs+=("$storepath"/lib/*.so.*)
+    fi
+    if [[ -d "$storepath/share" ]]; then
+      add_to_share+=("$storepath/share")
+    fi
+    if >/dev/null compgen -G "$storepath/lib/python*/site-packages"; then
+      add_to_pythonpath+=("$storepath"/lib/python*/site-packages)
+    fi
+  done
+
+  if [[ "${#add_to_path[@]}" -gt 0 ]]; then
+    export PATH="$(IFS=: ; printf "%s" "${add_to_path[*]}")${PATH:+":$PATH"}"
+  fi
+  if [[ "${#add_to_libs[@]}" -gt 0 ]]; then
+    export NIX_LDFLAGS="$(IFS=" " ; printf "-L%s" "${add_to_libs[*]}")${NIX_LDFLAGS:+" $NIX_LDFLAGS"}"
+    export LD_LIBRARY_PATH="$(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:+":$CPATH"}"
+  fi
+  if [[ "${#add_to_pythonpath[@]}" -gt 0 ]]; then
+    export PYTHONPATH="$(IFS=: ; printf "%s" "${add_to_pythonpath[*]}")${PYTHONPATH:+":$PYTHONPATH"}"
+    # export PYTHONNOUSERSITE=1
+  fi
 }