tlshell failure on x86_64-linux

[Robert Alessi]

Hello,

I just tried to launch tlshell on pretest as a normal user, but I got
the following instead.  Everything else works perfectly so far.

---------------------%>---------------------
$ tlshell
Error in startup script: couldn't open "/usr/local/texlive/2020/1135": permission denied
    while executing
"open $newfile w"
    invoked from within
"if [file exists $newfile] {
      continue
    } else {
      set fid [open $newfile w]
      chan close $fid
      if [file exists $newfile] {
      ..."
    (procedure "dir_writable" line 5)
    invoked from within
"dir_writable $::instroot"
    (procedure "initialize" line 64)
    invoked from within
"initialize"
    (file "/usr/local/texlive/2020/bin/x86_64-linux/tlshell" line 2422)
---------------------%>---------------------

Best,

Robert