unexpected propagation of <const> attribute

[fperrad]

local utf8 = utf8
if not utf8 then
   local ok, lutf8 = pcall(require, 'lua-utf8')
   if ok then
      utf8 = lutf8  -- Error: cannot assign to <const> variable
   end
end

The global utf8 has the attribute.
But the local utf8 inherits of this attribute.

$ tl check const.tl 
========================================
2 errors:
const.tl:3:27: module not found: 'lua-utf8'
const.tl:5:7: cannot assign to <const> variable

[hishamhm]

@fperrad I fixed this in the next branch! It should now allow the pattern that you described. (See testcase in 181d2a5).

I haven't been backporting fixes to master because I'm really in the final stretch for the next branch (hoping to release Sep/Oct). Could you give next a try?

(Also, if you're using --gen-compat then utf8 compatibility should come for free via compat-5.3 — but IIRC you're not using it because of the bit operations? Is that the case?)

Thank you for the report!