fix: man_pages previewer, respecting MANPATH and apropos output parsing (#1764)

- introducing putils writer and use it rather than using PAGER env var
- introducing env for lua/telescope/_.lua job interface
  - to respect MANPATH (and PATH just in case)
- fix for apropos output parsing might return e.g. `alacritty, Alacritty`
  We need to split on first `,`

lua/telescope/previewers/buffer_previewer.lua

@@ -610,7 +610,7 @@ end, {})
 
 previewers.man = defaulter(function(opts)
   local pager = utils.get_lazy_default(opts.PAGER, function()
-    return vim.fn.executable "col" == 1 and "col -bx" or ""
+    return vim.fn.executable "col" == 1 and { "col", "-bx" } or { "cat" }
   end)
   return previewers.new_buffer_previewer {
     title = "Man Preview",
@@ -620,8 +620,9 @@ previewers.man = defaulter(function(opts)
 
     define_preview = function(self, entry, status)
       local win_width = vim.api.nvim_win_get_width(self.state.winid)
-      putils.job_maker({ "man", entry.section, entry.value }, self.state.bufnr, {
-        env = { ["PAGER"] = pager, ["MANWIDTH"] = win_width },
+      putils.job_maker(vim.deepcopy(pager), self.state.bufnr, {
+        writer = { "man", entry.section, entry.value },
+        env = { ["MANWIDTH"] = win_width, PATH = vim.env.PATH, MANPATH = vim.env.MANPATH },
         value = entry.value .. "/" .. entry.section,
         bufname = self.state.bufname,
       })

lua/telescope/previewers/utils.lua

@@ -33,12 +33,25 @@ utils.job_maker = function(cmd, bufnr, opts)
   -- if any of them are missing, cache will be skipped
   if opts.bufname ~= opts.value or not opts.bufname or not opts.value then
     local command = table.remove(cmd, 1)
+    local writer = (function()
+      if opts.writer ~= nil then
+        local wcommand = table.remove(opts.writer, 1)
+        return Job:new {
+          command = wcommand,
+          args = opts.writer,
+          env = opts.env,
+          cwd = opts.cwd,
+        }
+      end
+    end)()
+
     Job
       :new({
         command = command,
         args = cmd,
         env = opts.env,
         cwd = opts.cwd,
+        writer = writer,
         on_exit = vim.schedule_wrap(function(j)
           if not vim.api.nvim_buf_is_valid(bufnr) then
             return