Unavailable Tcl version when compiling for MacOS 10.6

[lmbelo]

Bug report

MacOS build-installer.py script failing with the --dep-target=10.6 argument. It tries to download an unavailable Tcl version (8.6.12) from the FTP server.

Error

urllib.error.URLError: <urlopen error ftp error: URLError("ftp error: error_perm('550 Failed to change directory.')")>

Your environment

• CPython versions tested on: 3.10.4
• Operating system and architecture: MacOS M1

[erlend-aasland]

Quoting the Tcl/Tk website:

The main site for Tcl/Tk source distributions is SourceForge

The link they provide for 8.6.12 is https://prdownloads.sourceforge.net/tcl/tcl8.6.12-src.tar.gz

[lmbelo]

It works well using the SourceForge link.

[erlend-aasland]

For the record:

$ wget ftp://ftp.tcl.tk/pub/tcl//tcl8_6/tcl8.6.8-src.tar.gz
--2022-05-02 13:02:17--  ftp://ftp.tcl.tk/pub/tcl//tcl8_6/tcl8.6.8-src.tar.gz
           => ‘tcl8.6.8-src.tar.gz.1’
Resolving ftp.tcl.tk (ftp.tcl.tk)... 66.228.49.43
Connecting to ftp.tcl.tk (ftp.tcl.tk)|66.228.49.43|:21... connected.
Logging in as anonymous ... Logged in!
==> SYST ... done.    ==> PWD ... done.
==> TYPE I ... done.  ==> CWD (1) /pub/tcl//tcl8_6 ... done.
==> SIZE tcl8.6.8-src.tar.gz ... 9793786
==> PASV ... done.    ==> RETR tcl8.6.8-src.tar.gz ... done.
Length: 9793786 (9,3M) (unauthoritative)

tcl8.6.8-src.tar.gz.1                                       100%[=========================================================================================================================================>]   9,34M  5,31MB/s    in 1,8s    

2022-05-02 13:02:20 (5,31 MB/s) - ‘tcl8.6.8-src.tar.gz.1’ saved [9793786]

$ wget ftp://ftp.tcl.tk/pub/tcl//tcl8_6/tcl8.6.12-src.tar.gz
--2022-05-02 13:02:23--  ftp://ftp.tcl.tk/pub/tcl//tcl8_6/tcl8.6.12-src.tar.gz
           => ‘tcl8.6.12-src.tar.gz.1’
Resolving ftp.tcl.tk (ftp.tcl.tk)... 66.228.49.43
Connecting to ftp.tcl.tk (ftp.tcl.tk)|66.228.49.43|:21... connected.
Logging in as anonymous ... Logged in!
==> SYST ... done.    ==> PWD ... done.
==> TYPE I ... done.  ==> CWD (1) /pub/tcl//tcl8_6 ... done.
==> SIZE tcl8.6.12-src.tar.gz ... done.

==> PASV ... done.    ==> RETR tcl8.6.12-src.tar.gz ... 
No such file ‘tcl8.6.12-src.tar.gz’.

[ronaldoussoren]

The SourceForge download link is problematic for the build script because it inserts an intermediate page and that breaks the build-installer.py script.

A somewhat easy fix would be to change the downloadURL function in that script to use curl(1) instead of urllib to download. I checked that curl -LO https://prdownloads.sourceforge.net/tcl/tcl8.6.12-src.tar.gz will download the source archive.

[erlend-aasland]

Good point regarding the redirects. Using curl is a better option.

[ronaldoussoren]

Calling out to curl is the easy option, it Is also possible to follow redirects in Python code but that's more work and probably not worth the effort for this script.

[zware]

We do keep a copy of the vanilla tcl/tk sources in our own GitHub repo for use on Windows, though the link GitHub gives to the archive is also a redirect (https://github.com/python/cpython-source-deps/archive/refs/tags/tcl-core-8.6.12.0.tar.gz -> https://codeload.github.com/python/cpython-source-deps/tar.gz/refs/tags/tcl-core-8.6.12.0; similar for tk). We also only use the tcl-core package rather than the full-fat tcl distribution; we've found that's all we actually need on Windows.