bug#34085: autoscan reports a warning

bug#34085: autoscan reports a warning

[Joshua Branson]

Hello,

I'm not certain if this is the right list to report this to, but I just
installed autoscan version 2.21, and it gave me this warning:

#BEGIN_SRC sh
  autoscan
#END_SRC

Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/\${ <-- HERE [^\}]*}/ at /home/joshua/.guix-profile/bin/autoscan line 361.


Should I report this upstream instead?

Thanks

--
Joshua Branson
Sent from Emacs and Gnus

bug#34085: autoscan reports a warning

[Ludovic Courtès]

Hi,

Joshua Branson <jbranso@dismail.de> skribis:

> I'm not certain if this is the right list to report this to, but I just
> installed autoscan version 2.21, and it gave me this warning:

Guix doesn’t have an ‘autoscan’ package, does it?

Ludo’.

bug#34085: autoscan reports a warning

[Danny Milosavljevic]

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Hi,

On Tue, 15 Jan 2019 10:43:49 -0500
Joshua Branson <jbranso@dismail.de> wrote:

> I'm not certain if this is the right list to report this to, but I just
> installed autoscan version 2.21, and it gave me this warning:
> 
> #BEGIN_SRC sh
>   autoscan
> #END_SRC
> 
> Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/\${ <-- HERE [^\}]*}/ at /home/joshua/.guix-profile/bin/autoscan line 361.
> 
> 
> Should I report this upstream instead?

I think so, yes.

autoscan is part of autoconf 2.21, so the bug report should go to the autoconf package.

The regexp in question is

      s/\${[^\}]*}//g;

Perl is complaining because perl regexp use curly braces to specify a range of valid repeats.
Maybe the easiest way to understand it is that the following equivalences hold in regexps:

? is equivalent to {0,1}
+ is equivalent to {1,}
* is equivalent to {0,}

The above (at the end of the regexp "\${[^\}]*}") probably means a literal curly
brace--but they don't escape it - hence the warning.

It's only a warning because no valid repeat range can start with a closing curly
brace.
So perl can still figure out what you meant.

But it's obviously not recommended to use unescaped closing curly braces to
match a literal closing curly brace regardless.

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bug#34085: autoscan reports a warning

[Joshua Branson]

Danny Milosavljevic <dannym@scratchpost.org> writes:

> Hi,
>
> On Tue, 15 Jan 2019 10:43:49 -0500
> Joshua Branson <jbranso@dismail.de> wrote:
>
>> I'm not certain if this is the right list to report this to, but I just
>> installed autoscan version 2.21, and it gave me this warning:
>> 
>> #BEGIN_SRC sh
>>   autoscan
>> #END_SRC
>> 
>> Unescaped left brace in regex is deprecated here (and will be fatal
>> in Perl 5.30), passed through in regex; marked by <-- HERE in m/\${
>> <-- HERE [^\}]*}/ at /home/joshua/.guix-profile/bin/autoscan line
>> 361.
>> 
>> 
>> Should I report this upstream instead?
>
> I think so, yes.
>
> autoscan is part of autoconf 2.21, so the bug report should go to the autoconf package.
>
> The regexp in question is
>
>       s/\${[^\}]*}//g;
>
> Perl is complaining because perl regexp use curly braces to specify a range of valid repeats.
> Maybe the easiest way to understand it is that the following equivalences hold in regexps:
>
> ? is equivalent to {0,1}
> + is equivalent to {1,}
> * is equivalent to {0,}
>
> The above (at the end of the regexp "\${[^\}]*}") probably means a literal curly
> brace--but they don't escape it - hence the warning.
>
> It's only a warning because no valid repeat range can start with a closing curly
> brace.
> So perl can still figure out what you meant.
>
> But it's obviously not recommended to use unescaped closing curly braces to
> match a literal closing curly brace regardless.
>


Ok, I'll report this upstream.  Thanks for flushing out the main issue!

-- 
Joshua Branson
Sent from Emacs and Gnus