Setup shows errors from gnuplot-base.dash and python38-devel.sh

[Ken Brown]

On 7/14/2021 9:20 PM, Doug Henderson via Cygwin wrote:
> On Wed, 14 Jul 2021 at 16:33, Ken Brown via Cygwin <cygwin@cygwin.com> wrote:
>>
>> On 7/14/2021 5:08 PM, Doug Henderson via Cygwin wrote:
>>> On Wed, 14 Jul 2021 at 13:03, Achim Gratz <Stromeko@nexgo.de> wrote:
>>>>
>>>> Doug Henderson via Cygwin writes:
>>>>> The first error message occurred when I installed all pending packages
>>>>> this morning. I hoped to heal the problem by reinstalling the
>>>>> installed gnuplot packages. Now I get both the messages.
>>>>
>>>> If you look in /var7Log/setup.log.full you should be able to see what
>>>> error messages, if any, were recorded.
>>>>
>>>> The gnuplot related script should just set up the current alternative
>>>> for "gnuplot" to use, but something on your system seems to prevent
>>>> that from happening.  You can also run the script in sh (you must tell
>>>> the shell to source it) and should get the same error (most likely).
>>>
>>> When I do that in an elevated shell:
>>>
>>> $ cd /etc/postinstall/
>>>
>>> $ cat gnuplot-base.dash
>>> /usr/sbin/alternatives --install /usr/bin/gnuplot gnuplot
>>> /usr/bin/gnuplot-base.exe 10
>>>
>>> $ . gnuplot-base.dash
>>> failed to read link /usr/bin/gnuplot: No such file or directory
>>> failed to link /usr/bin/gnuplot -> /etc/alternatives/gnuplot: No such
>>> file or directory
>>
>> Something seems to be confusing 'alternatives'.  Can you show a listing of
>> /etc/alternatives?
> 
> $ cd /etc/alternatives/
> 
> $ ls -l
> total 2.0K
> lrwxrwxrwx 1 Admin None  35 Oct  3  2017 automake-doc ->
> /usr/share/info/automake1.9.info.gz
> lrwxrwxrwx 1 Admin None  19 Jun 16 17:48 lua -> /usr/bin/lua5.3.exe*
> lrwxrwxrwx 1 Admin None  31 Jun 16 17:48 lua.1.gz ->
> /usr/share/man/man1/lua5.3.1.gz
> lrwxrwxrwx 1 Admin None  20 Jun 16 17:48 luac -> /usr/bin/luac5.3.exe*
> lrwxrwxrwx 1 Admin None  32 Jun 16 17:48 luac.1.gz ->
> /usr/share/man/man1/luac5.3.1.gz
> lrwxrwxrwx 1 Admin None  15 Jun  5 08:46 pip3 -> /usr/bin/pip3.8*
> lrwxrwxrwx 1 Admin None  22 Jun 16 07:34 python -> /usr/bin/python3.8.exe*
> -rw-r--r-- 1 Admin None 163 Apr  4  2013 README

This shows that alternatives worked in June.  Have you changed anything since 
then that might be related to symlinks (e.g., the CYGWIN environment variable)?

Here are a few other things you could try:

1. Attach cygcheck output as requested in https://cygwin.com/problems.html

2. Add --verbose to the alternatives call.

3. Run the alternatives call under strace and look for errors involving 
symlinks.  Or post the output somewhere so that we can look at it.

Ken