Extensions check for Perl dependencies

reproduced with Inkscape 0.46 and Inkscape 0.47+devel r8898 on OS X 10.5.8

The perl script 'extensions/txt2svg.pl' depends on the SVG module which is not included in the default Perl installation on OS X.

SVG - Perl extension for generating Scalable Vector Graphics (SVG) documents
<http://search.cpan.org/search%3fmodule=SVG>

me too on Mac OS X 10.4.11

Sorry if I'm being stupid, but I'm not aware of how to import *.txt files. The file type is not listed in the "File->Import..." or "File->Open..>" dialogs.

Attempting to open/import a txt file by using "All Files" from either of these dialogs just gives me a dialog with the message: "Failed to load the requested file /home/alex/Documents/Text/text.txt"

On a separate note, Ubuntu already Suggests libsvg-perl, which adds SVG.pm and fixes the problem in comment #2. The ideal solution would be to bump this up to "Recommends" status so that it is automatically installed along with Inkscape. However, this is not possible because Inkscape is a "main" package (i.e. officially supported) while libsvg-perl is a "universe" package (i.e. community supported).

> I'm not aware of how to import *.txt files. The file type is not listed in
> the "File->Import..." or "File->Open..>" dialogs.

If the file type is not listed, one of the dependencies in 'txt2svg.inx' is not fulfilled:

    <dependency type="executable" location="extensions">txt2svg.pl</dependency>
    <dependency type="executable" location="path">perl</dependency>

i.e. either the extension script is missing (incomplete installation?), or Inkscape cannot find 'perl' in your $PATH?

related files in the 0.48.x branch:
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/RELEASE_0_48_BRANCH/annotate/head%3A/share/extensions/txt2svg.inx>
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/RELEASE_0_48_BRANCH/annotate/head%3A/share/extensions/txt2svg.pl>

Please check the contents of '~/.config/inkscape/extension-errors.log' if it gives any clues why the extension fails to load.
Is the perl script set as 'executable' in your installation (/usr/share/inkscape/extensions/txt2svg.pl)?

> The file type is not listed in the "File->Import..."
> or "File->Open..>" dialogs.

The file type is listed as "Text File (*.txt)" (quite far down in the list) if the extension is loaded; see line 10 in the extension definition file (txt2svg.inx):

        <_filetypename>Text File (*.txt)</_filetypename>

Curious (see below). Maybe I should open this as a new bug.

* perl is installed in /usr/bin (which is in my $PATH)
ls -l /usr/bin/perl
-rwxr-xr-x 2 root root 1240796 2010-07-12 12:42 /usr/bin/perl

* txt2svg.pl is executable
ls -l /usr/share/inkscape/extensions/txt2svg.pl
-rwxr-xr-x 1 root root 649 2010-10-19 02:25 /usr/share/inkscape/extensions/txt2svg.pl

* extension-errors.log does not mention anything about the extension
Extension "XFIG Input" failed to load because a dependency was not met.
Dependency:
  type: executable
  location: path
  string: fig2dev

Extension "Sketch Input" failed to load because a dependency was not met.
Dependency:
  type: executable
  location: path
  string: skconvert

Extension "Dia Input" failed to load because a dependency was not met.
Dependency:
  type: executable
  location: path
  string: dia
  description: In order to import Dia files, Dia itself must be installed. You can get Dia at http://live.gnome.org/Dia

(emailed inkscape-devel for debugging assistance)

confirmed on Windows XP, Inkscape .48. I have Perl installed, but no .txt file extension available as an import. The workaround is to delete the following line from the file txt2svg.inx:

<check reldir="extensions">txt2svg.pl</check>

With the new inx file the .txt extension appears just below the sk1 extension. When I now try to load a .txt file I get the message:

Can't locate SVG.pm in @INC (@INC contains: C:/Perl/site/lib C:/Perl/lib .) at txt2svg.pl line 6.
BEGIN failed--compilation aborted at txt2svg.pl line 6.

This could be fixed by installing the SVG module, which I don't feel like doing.

fwiw, there appear to be only 2 extensions that use the command <check reldir .
They are both perl extensions. The other one is called outline2svg.pl

> The workaround is to delete the following line from the file txt2svg.inx:
  <check reldir="extensions">txt2svg.pl</check>
> With the new inx file the .txt extension appears just below the sk1 extension.

In Inkscape 0.48 and 0.48+devel r9862 on OS X 10.5.8 I do see both file types listed in the 'File open' dialog _without_ changing any line of the extension definition files (outline2svg.inx, txt2svg.inx). (Yes, I removed the user extensions directory before testing, and checked the shared extensions directory for duplicate file types).

Possibly the <check reldir="…></check> fails on Windows?

The extensions fail with the same error message as initially reported because SVG.pm is not installed on the system.

> Possibly the <check reldir="…></check> fails on Windows?

Maybe it is the other way round and the command <check …></check> "fails" on OS X?
Changing it to (non-existent)
        <check reldir="extensions">txt2foo.pl</check>
doesn't prevent the extension from being loaded on OS X -- i.e. the <check> command seems completely ignored and the input file format for *.txt listed anyway in the 'File open' dialog.

Changing the dependency check (to non-existent)
    <dependency type="executable" location="extensions">txt2foo.pl</dependency>
prevents the extension from loading though (file type not listed).

I think my inclination would be to permanently remove the line
<check reldir="extensions">txt2svg.pl</check>
from both of these extensions, unless someone has a specific reason for it to be there. I have a machine with no perl installed on it, and in this case the dependence on perl is caught properly by the line
<command reldir="extensions" interpreter="perl">txt2svg.pl</command>
which is the "normal" check that essentially all .inx files have. (I deleted the line <check reldir> and confirmed that the extensions-log file still showed that the perl dependency was not met.)

> I think my inclination would be to permanently remove the line
> <check reldir="extensions">txt2svg.pl</check>

As a workaround maybe, once it is confirmed that the same line prevents the extension from being loaded not only on Windows, but on Linux too. However - if so, it means there is broken code in the extension system and just removing what calls it doesn't really address the issue imho.

I'd rather see it investigated code-wise what broke that <check> feature (and why the result differs across platforms), have it fixed or removed in the source and after that all inx files updated correspondingly.

Commenting out that line (<check> tag) allows the extension to load on linux (Ubuntu 10.04).

As noted above a quick search only turns up 2 extensions using that tag:

/opt/inkscape-0.48/share/inkscape/extensions$ grep -RHin "<check" .
./txt2svg.inx:15: <check reldir="extensions">txt2svg.pl</check>
./outline2svg.inx:15: <check reldir="extensions">outline2svg.pl</check>

The second extension - outline2svg - also does not load unless the <check> tag is commented out. Again nothing in the extension-errors log for that one either.

So - there are two issues: 1. the ubuntu package needs a dependency on libsvg-perl, and 2. something is not working correctly in Inkscape's handling of the <check> tag.

IMO this bug would be fixed by addressing #1 and a separate bug should be opened against Inkscape for #2.

Thanks to everyone for your work on this. While the upstream work is being carried out, I'll prepare a new package for Ubuntu with the "<check>" tags removed.

We already have the relationship "inkscape suggests libsvg-perl" in Ubuntu. Unfortunately, we can't change it to "inkscape recommends libsvg-perl" which would automatically install libsvg-perl. This is because inkscape is in the main repository (i.e. officially supported by Canonical) but libsvg-perl is in the universe repository (i.e. community supported).

To avoid confusion, I will open a separate report to deal with the failure to load extensions with <check> tags.

New report opened as bug #668895 to deal with the <check> tags issue

Marking this as "Won't Fix" in Ubuntu, for the reasons previously discussed. Unfortunately, the required perl module is community-supported and cannot be installed automatically.

Bug #668895 fixed in the trunk, revision 10020.

But the extension still doesn't work if the required Perl modules (strict, etc.) are not installed.

Closely related: Bug #174992 "Extensions check for Python dependencies"
<https://bugs.launchpad.net/inkscape/+bug/174992>

Closing because there are no perl extensions shipped with Inkscape anymore, starting with Inkscape 1.0.

Closed by: https://gitlab.com/jhofinger