Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Adam Porter]

"Loris Bennett"  writes:

>> I and others have asked a few times why the packages are structured in
>> this way, but nobody seems able to provide the rationale. Personally, I
>> think we should just have an org package and an org-contrib package
>> which depends on the org package.
>>
>> Tim
>>
>
> So is there a specific reason why there is no 'org-contrib' package
> without 'org'?

Yes, that would seem to make more sense.

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Loris Bennett]

Tim Cross  writes:

> Loris Bennett writes:
>
>> Adam Porter  writes:
>>
>>> "Loris Bennett"  writes:
>>>
 I didn't know about this function either.  Is it correct that the org
 parts of 'org-plus-contrib' shadow the whole of 'org', e.g.

   ...
   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org hides 
 /usr/share/emacs/25.1/lisp/org/org
   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-install hides 
 /usr/share/emacs/25.1/lisp/org/org-install
   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-mscgen hides 
 /usr/share/emacs/25.1/lisp/org/ob-mscgen
   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-archive hides 
 /usr/share/emacs/25.1/lisp/org/org-archive
   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-tangle hides 
 /usr/share/emacs/25.1/lisp/org/ob-tangle
   ...
   
 plus hundreds of similar shadowings?
>>>
>>> That's shadowing the Org files distributed with Emacs; you want that.  :)
>>
>> D'oh, I copied the wrong bits.  This was what I was wondering about:
>>
>>   ...
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ox-md hides 
>> /home/loris/.emacs.d/elpa/org-20170828/ox-md
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-lilypond hides 
>> /home/loris/.emacs.d/elpa/org-20170828/ob-lilypond
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-ruby hides 
>> /home/loris/.emacs.d/elpa/org-20170828/ob-ruby
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-js hides 
>> /home/loris/.emacs.d/elpa/org-20170828/ob-js
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-crypt hides 
>> /home/loris/.emacs.d/elpa/org-20170828/org-crypt
>>   ...
>>
>> M-x list-packages shows 'org-plus-contrib' as installed and 'org' as a
>> dependency required by
>>
>>   ox-twiki-20170803.1339, org-sticky-header-20170422.2135, 
>> org-dotemacs-20151119.1022
>>
>> So I guess the above packages should allow 'org-plus-contrib' as an
>> alternative requirement to 'org', but currently require only 'org', so I
>> end up with both installed.
>>
>> Cheers,
>>
>> Loris
>
> This is an artefact of having the two packages. The package system does
> not support alternatives. I have posted a few times regarding this. I
> don't think it does any harm, but many people will find they have both
> org-plus-contrib as well as org installed. The main draw back is that
> updates can take longer due to downloading org twice. 
>
> I and others have asked a few times why the packages are structured in
> this way, but nobody seems able to provide the rationale. Personally, I
> think we should just have an org package and an org-contrib package
> which depends on the org package.
>
> Tim
>

So is there a specific reason why there is no 'org-contrib' package
without 'org'?

Cheers,

Loris

-- 
Dr. Loris Bennett (Mr.)
ZEDAT, Freie Universität Berlin Email loris.benn...@fu-berlin.de

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Tim Cross]

This is an artefact of having the two packages. The package system does
not support alternatives. I have posted a few times regarding this. I
don't think it does any harm, but many people will find they have both
org-plus-contrib as well as org installed. The main draw back is that
updates can take longer due to downloading org twice. 

I and others have asked a few times why the packages are structured in
this way, but nobody seems able to provide the rationale. Personally, I
think we should just have an org package and an org-contrib package
which depends on the org package.

Tim

Loris Bennett writes:

> Adam Porter  writes:
>
>> "Loris Bennett"  writes:
>>
>>> I didn't know about this function either.  Is it correct that the org
>>> parts of 'org-plus-contrib' shadow the whole of 'org', e.g.
>>>
>>>   ...
>>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org hides 
>>> /usr/share/emacs/25.1/lisp/org/org
>>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-install hides 
>>> /usr/share/emacs/25.1/lisp/org/org-install
>>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-mscgen hides 
>>> /usr/share/emacs/25.1/lisp/org/ob-mscgen
>>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-archive hides 
>>> /usr/share/emacs/25.1/lisp/org/org-archive
>>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-tangle hides 
>>> /usr/share/emacs/25.1/lisp/org/ob-tangle
>>>   ...
>>>   
>>> plus hundreds of similar shadowings?
>>
>> That's shadowing the Org files distributed with Emacs; you want that.  :)
>
> D'oh, I copied the wrong bits.  This was what I was wondering about:
>
>   ...
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ox-md hides 
> /home/loris/.emacs.d/elpa/org-20170828/ox-md
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-lilypond hides 
> /home/loris/.emacs.d/elpa/org-20170828/ob-lilypond
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-ruby hides 
> /home/loris/.emacs.d/elpa/org-20170828/ob-ruby
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-js hides 
> /home/loris/.emacs.d/elpa/org-20170828/ob-js
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-crypt hides 
> /home/loris/.emacs.d/elpa/org-20170828/org-crypt
>   ...
>
> M-x list-packages shows 'org-plus-contrib' as installed and 'org' as a
> dependency required by
>
>   ox-twiki-20170803.1339, org-sticky-header-20170422.2135, 
> org-dotemacs-20151119.1022
>
> So I guess the above packages should allow 'org-plus-contrib' as an
> alternative requirement to 'org', but currently require only 'org', so I
> end up with both installed.
>
> Cheers,
>
> Loris


-- 
Tim Cross

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Loris Bennett]

Adam Porter  writes:

> "Loris Bennett"  writes:
>
>> I didn't know about this function either.  Is it correct that the org
>> parts of 'org-plus-contrib' shadow the whole of 'org', e.g.
>>
>>   ...
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org hides 
>> /usr/share/emacs/25.1/lisp/org/org
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-install hides 
>> /usr/share/emacs/25.1/lisp/org/org-install
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-mscgen hides 
>> /usr/share/emacs/25.1/lisp/org/ob-mscgen
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-archive hides 
>> /usr/share/emacs/25.1/lisp/org/org-archive
>>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-tangle hides 
>> /usr/share/emacs/25.1/lisp/org/ob-tangle
>>   ...
>>   
>> plus hundreds of similar shadowings?
>
> That's shadowing the Org files distributed with Emacs; you want that.  :)

D'oh, I copied the wrong bits.  This was what I was wondering about:

  ...
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ox-md hides 
/home/loris/.emacs.d/elpa/org-20170828/ox-md
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-lilypond hides 
/home/loris/.emacs.d/elpa/org-20170828/ob-lilypond
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-ruby hides 
/home/loris/.emacs.d/elpa/org-20170828/ob-ruby
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-js hides 
/home/loris/.emacs.d/elpa/org-20170828/ob-js
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-crypt hides 
/home/loris/.emacs.d/elpa/org-20170828/org-crypt
  ...

M-x list-packages shows 'org-plus-contrib' as installed and 'org' as a
dependency required by

  ox-twiki-20170803.1339, org-sticky-header-20170422.2135, 
org-dotemacs-20151119.1022

So I guess the above packages should allow 'org-plus-contrib' as an
alternative requirement to 'org', but currently require only 'org', so I
end up with both installed.

Cheers,

Loris

-- 
Dr. Loris Bennett (Mr.)
ZEDAT, Freie Universität Berlin Email loris.benn...@fu-berlin.de

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Adam Porter]

"Loris Bennett"  writes:

> I didn't know about this function either.  Is it correct that the org
> parts of 'org-plus-contrib' shadow the whole of 'org', e.g.
>
>   ...
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org hides 
> /usr/share/emacs/25.1/lisp/org/org
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-install hides 
> /usr/share/emacs/25.1/lisp/org/org-install
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-mscgen hides 
> /usr/share/emacs/25.1/lisp/org/ob-mscgen
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-archive hides 
> /usr/share/emacs/25.1/lisp/org/org-archive
>   /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-tangle hides 
> /usr/share/emacs/25.1/lisp/org/ob-tangle
>   ...
>   
> plus hundreds of similar shadowings?

That's shadowing the Org files distributed with Emacs; you want that.  :)

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Loris Bennett]

Kaushal Modi  writes:

> On Fri, Sep 1, 2017, 10:49 PM Adam Porter  wrote:
>
>  Kaushal Modi  writes:
>
>  > M-x list-load-path-shadows will also help. Pay attention to shadows on org 
> packages.
>
>  Wow, I did not know about that command. I have a bit of cleaning-up to
>  do. :)
>
> That's what I did when I found the shadows too :)
>
> Here's how I make sure no mixed installations happen among
> Emacs-built-in, Elpa and git Org versions:
> https://scripter.co/building-org-development-version/
>
> In addition to load-path, I also handle Info-path so that the correct
> Org manual gets loaded.

I didn't know about this function either.  Is it correct that the org
parts of 'org-plus-contrib' shadow the whole of 'org', e.g.

  ...
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org hides 
/usr/share/emacs/25.1/lisp/org/org
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-install hides 
/usr/share/emacs/25.1/lisp/org/org-install
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-mscgen hides 
/usr/share/emacs/25.1/lisp/org/ob-mscgen
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/org-archive hides 
/usr/share/emacs/25.1/lisp/org/org-archive
  /home/loris/.emacs.d/elpa/org-plus-contrib-20170828/ob-tangle hides 
/usr/share/emacs/25.1/lisp/org/ob-tangle
  ...
  
plus hundreds of similar shadowings?

Cheers,

Loris

-- 
Dr. Loris Bennett (Mr.)
ZEDAT, Freie Universität Berlin Email loris.benn...@fu-berlin.de

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Adam Porter]

Wow, thanks, that is comprehensive.  :)

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Kaushal Modi]

On Fri, Sep 1, 2017, 10:49 PM Adam Porter  wrote:

> Kaushal Modi  writes:
>
> > M-x list-load-path-shadows will also help. Pay attention to shadows on
> org packages.
>
> Wow, I did not know about that command.  I have a bit of cleaning-up to
> do.  :)
>

That's what I did when I found the shadows too :)

Here's how I make sure no mixed installations happen among Emacs-built-in,
Elpa and git Org versions:
https://scripter.co/building-org-development-version/

In addition to load-path, I also handle Info-path so that the correct Org
manual gets loaded.

-- 

Kaushal Modi

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Adam Porter]

Kaushal Modi  writes:

> M-x list-load-path-shadows will also help. Pay attention to shadows on org 
> packages. 

Wow, I did not know about that command.  I have a bit of cleaning-up to
do.  :)

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Sam Halliday]

By running this

  (cl-delete-if
   (lambda (el) (string-match-p "/usr/share/.*org" el))
   load-path)

I'm able to hide org and now the org-plus-contrib loads up, yay!
Thanks for the hints.



On 21 August 2017 at 01:40, Kaushal Modi  wrote:
> On Sun, Aug 20, 2017, 4:25 PM Nicolas Goaziou 
> wrote:
>>
>>
>> > then I can try to investigate what could be causing the Emacs org
>> > to load. I cannot see how that is possible since it is not even
>> > available on the elisp path anymore.
>> >
>> > Is there a way to check which elisp files have been loaded? Then I can
>> > grep for anything from the emacs org install instead of my local
>> > install.
>>
>> `locate-library' may help. Also, `load-path' can give a clue. Try with
>> a bare configuration, i.e., with just
>>
>>   (require 'package)
>>   (package-initialize)
>>
>> It can be tricky to find out what is loading bundled Org too early.
>> Enjoy the Frankenorg.
>
>
> :)
>
> M-x list-load-path-shadows will also help. Pay attention to shadows on org
> packages.
>
> --
>
> Kaushal Modi

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Kaushal Modi]

On Sun, Aug 20, 2017, 4:25 PM Nicolas Goaziou 
wrote:

>
> > then I can try to investigate what could be causing the Emacs org
> > to load. I cannot see how that is possible since it is not even
> > available on the elisp path anymore.
> >
> > Is there a way to check which elisp files have been loaded? Then I can
> > grep for anything from the emacs org install instead of my local
> > install.
>
> `locate-library' may help. Also, `load-path' can give a clue. Try with
> a bare configuration, i.e., with just
>
>   (require 'package)
>   (package-initialize)
>
> It can be tricky to find out what is loading bundled Org too early.
> Enjoy the Frankenorg.
>

:)

M-x list-load-path-shadows will also help. Pay attention to shadows on org
packages.

> --

Kaushal Modi

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Nicolas Goaziou]

Sam Halliday  writes:

> If you are confirming that org is definitely compatible with my .org
> file

It is, although I didn't check the details of the output. It didn't
error in the process anyway.

> then I can try to investigate what could be causing the Emacs org
> to load. I cannot see how that is possible since it is not even
> available on the elisp path anymore.
>
> Is there a way to check which elisp files have been loaded? Then I can
> grep for anything from the emacs org install instead of my local
> install.

`locate-library' may help. Also, `load-path' can give a clue. Try with
a bare configuration, i.e., with just

  (require 'package)
  (package-initialize)

It can be tricky to find out what is loading bundled Org too early.
Enjoy the Frankenorg.

Regards,

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Sam Halliday]

On 20 August 2017 at 16:07, Nicolas Goaziou  wrote:
> Hello,
>
> Sam Halliday  writes:
>
>> To ensure that the Emacs-installed org-mode is not interfering, I
>> added this to my init
>>
>>   (cl-delete-if
>>(lambda (el) (string-match-p ".*org" el))
>>load-path)
>>
>> and I can confirm that emacs/org is not in my load-path.
>>
>> However, the backtrace still occurs.
>
> As I wrote, it is still a problem of mixed installation. Quoting the
> manual
>
>   Recent Emacs distributions include a packaging system which lets you
>   install Elisp libraries.  You can install Org with ‘M-x package-install
>   RET org’.
>
>   Important: you need to do this in a session where no ‘.org’ file has
>   been visited, i.e., where no Org built-in function have been loaded.
>   Otherwise autoload Org functions will mess up the installation.
>
>  Then, to make sure your Org configuration is taken into account,
>   initialize the package system with ‘(package-initialize)’ in your
>   ‘.emacs’ before setting any Org option.  If you want to use Org’s
>   package repository, check out the Org ELPA page
>   (http://orgmode.org/elpa.html).

Yes, I followed this exactly and the problem still occurs.

If you are confirming that org is definitely compatible with my .org
file then I can try to investigate what could be causing the Emacs org
to load. I cannot see how that is possible since it is not even
available on the elisp path anymore.

Is there a way to check which elisp files have been loaded? Then I can
grep for anything from the emacs org install instead of my local
install.

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Nicolas Goaziou]

Hello,

Sam Halliday  writes:

> To ensure that the Emacs-installed org-mode is not interfering, I
> added this to my init
>
>   (cl-delete-if
>(lambda (el) (string-match-p ".*org" el))
>load-path)
>
> and I can confirm that emacs/org is not in my load-path.
>
> However, the backtrace still occurs.

As I wrote, it is still a problem of mixed installation. Quoting the
manual

  Recent Emacs distributions include a packaging system which lets you
  install Elisp libraries.  You can install Org with ‘M-x package-install
  RET org’.

  Important: you need to do this in a session where no ‘.org’ file has
  been visited, i.e., where no Org built-in function have been loaded.
  Otherwise autoload Org functions will mess up the installation.

 Then, to make sure your Org configuration is taken into account,
  initialize the package system with ‘(package-initialize)’ in your
  ‘.emacs’ before setting any Org option.  If you want to use Org’s
  package repository, check out the Org ELPA page
  (http://orgmode.org/elpa.html).

Some users install Org launching a new Emacs session without any
configuration file.

> For a much larger file that causes additional problems with org-mode
> markdown export (e.g. problems with BEGIN_SRC blocks) is my book's
> manuscript:
>
>   https://github.com/fommil/fp-scala-mortals/blob/master/manuscript/book.org

Could you point out what are the problems? I have no issue exporting the
document above with latest Org, but I may have missed some wrong bits in
the output. I have no Scala mode installed.

Regards,

-- 
Nicolas Goaziou

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Sam Halliday]

Hi Nicholas,

To ensure that the Emacs-installed org-mode is not interfering, I
added this to my init

  (cl-delete-if
   (lambda (el) (string-match-p ".*org" el))
   load-path)

and I can confirm that emacs/org is not in my load-path.

However, the backtrace still occurs.

For a much larger file that causes additional problems with org-mode
markdown export (e.g. problems with BEGIN_SRC blocks) is my book's
manuscript:

  https://github.com/fommil/fp-scala-mortals/blob/master/manuscript/book.org

I am able to successfully export this using the built-in org-mode.

Although I'm using additional extensions of md as per

  https://github.com/fommil/dotfiles/blob/master/.emacs.d/lisp/ox-leanpub.el

I'm restricting my experiments to stock org-md for now.


Best regards,
Sam

On 19 August 2017 at 10:50, Nicolas Goaziou  wrote:
> Hello,
>
> Sam Halliday  writes:
>
>> Regression in org-plus-contrib from http://orgmode.org/elpa/ vs version
>> distributed with Emacs 25.2.1
>>
>> Running
>>
>>   M-x md-org-export-to-markdown
>>
>> on a simple org file such as the following
>>
>> ==
>>
>> #+TITLE: Functional Programming in Scala for Mortals
>>
>> /Functional Programming in Scala for Mortals/ is a book aimed at Scala
>> developers with an Object Oriented background who wish to learn the
>> *Functional Programming* paradigm.
>> ==
>>
>> Causes the following backtrace:
>>
>> Debugger entered--Lisp error: (wrong-type-argument listp #("Functional 
>> Programming in Scala for Mortals" 0 43 (:parent (#1
>
> This usually mean that you have a mixed installation. You should check
> that the Org shipped with Emacs is not used.
>
> Regards,
>
> --
> Nicolas Goaziou

Re: [O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Nicolas Goaziou]

Hello,

Sam Halliday  writes:

> Regression in org-plus-contrib from http://orgmode.org/elpa/ vs version
> distributed with Emacs 25.2.1
>
> Running
>
>   M-x md-org-export-to-markdown
>
> on a simple org file such as the following
>
> ==
>
> #+TITLE: Functional Programming in Scala for Mortals
>
> /Functional Programming in Scala for Mortals/ is a book aimed at Scala
> developers with an Object Oriented background who wish to learn the
> *Functional Programming* paradigm.
> ==
>
> Causes the following backtrace:
>
> Debugger entered--Lisp error: (wrong-type-argument listp #("Functional 
> Programming in Scala for Mortals" 0 43 (:parent (#1

This usually mean that you have a mixed installation. You should check
that the Org shipped with Emacs is not used.

Regards,

-- 
Nicolas Goaziou

[O] Bug: markdown export errors on headers [9.0.9 (9.0.9-82-gb862c2-elpaplus @ /home/fommil/.emacs.d/elpa/org-plus-contrib-20170814/)]

[Sam Halliday]

Regression in org-plus-contrib from http://orgmode.org/elpa/ vs version
distributed with Emacs 25.2.1

Running

  M-x md-org-export-to-markdown

on a simple org file such as the following

==
#+TITLE: Functional Programming in Scala for Mortals

/Functional Programming in Scala for Mortals/ is a book aimed at Scala
developers with an Object Oriented background who wish to learn the
*Functional Programming* paradigm.
==

Causes the following backtrace:

Debugger entered--Lisp error: (wrong-type-argument listp #("Functional 
Programming in Scala for Mortals" 0 43 (:parent (#1
  org-element-set-contents(#("Functional Programming in Scala for Mortals" 0 43 
(:parent (#0
  apply(org-element-set-contents #("Functional Programming in Scala for 
Mortals" 0 43 (:parent (#0))) nil)
  #[257 
"\211\305\306\307#\310\311\211:\204\312\202\"\n@9\203!\nAA\202\"\n)\"\210\313\314
\211:\2043\312\202@\n@9\203?\nAA\202@\n)#\210\315\211 
\n;\203V\316\317\n#\202\\\320\nA@\"*\211;\203n\321\n\312\f$\202z\nA\322\nA@\f#\240\210\n+\210
 AA@\240\210@\240*\207" [new old element property value 
replace-regexp-in-string "\n" " " mapc #[(blob) "\305 
\211;\203\306\f\307\n$\202 \fA\310\fA@\n#\240\210\f+\207" [blob old value 
property element :parent org-add-props nil plist-put] 6] nil apply 
org-element-set-contents :parent get-text-property 0 plist-get org-add-props 
plist-put] 7 "\n\n(fn S)"](#("Functional Programming in Scala for Mortals" 0 43 
(:parent (#0
  #[257 
"\211\211:\204\211;\205\311\262\202\211@9\205\211@\262
?\206\251\301\203-
\312\301\313\">\206\251\211\2049\314\310\242\"\202\251\211\315=\203]\314\310\242\211:\204N\316\262\202Y\211@9\203Y\211AA\262\"\202\251\211\304>\203~\300!\211\203}\302\203v\317\320\"\210\202}\307\307\242B\240\210\210\306\321=\203\271
;\204\271\211\236A\211\203\270\211@\310\242\211;\203\247\322\323#\266\202\202\257\312A@\"\266\202!\210A\266\202\202\216\210\303\203Q\306\321=\203Q\324!\325=\203Q\211\203P\211@\211@A\211;\203\347\322\323#\266\202\202\357\312A@\"\266\202\211\203G
\235\2030
\235\203!\326!\211\203
\211@\310\242A!\210\310\242@!\210A\266\202\202
\210\202G\310\242A!\210\310\242@!\210\202G
\235\203B\314\310\242\326!\"\210\202G\310\242!\210\266
A\266\202\202\315\210\211\305>\206\251
\211:\204c\316\262\202n\211@9\203n\211AA\262?\206\251\306\327=\203\200\211>?\206\251\306\330=\203\216\324!\331=\206\251\314\310\242\211:\204\235\316\262\202\250\211@9\203\250\211AA\262\"\207"
 [#[257 
"\211\305\306\307#\310\311\211:\204\312\202\"\n@9\203!\nAA\202\"\n)\"\210\313\314
   \211:\2043\312\202@\n@9\203?\nAA\202@\n)#\210\315\211 
\n;\203V\316\317\n#\202\\\320\nA@\"*\211;\203n\321\n\312\f$\202z\nA\322\nA@\f#\240\210\n+\210
 AA@\240\210@\240*\207" [new old element property value 
replace-regexp-in-string "\n" " " mapc #[(blob) "\305 
\211;\203\306\f\307\n$\202 \fA\310\fA@\n#\240\210\f+\207" [blob old value 
property element :parent org-add-props nil plist-put] 6] nil apply 
org-element-set-contents :parent get-text-property 0 plist-get org-add-props 
plist-put] 7 "\n\n(fn S)"] nil nil nil (plain-text) nil objects (nil) (#0) 
plain-text plist-get :ignore-list mapc org-data nil throw :--map-first-match 
objects get-text-property 0 org-element-class element reverse greater-elements 
elements object org-element-secondary-value-alist 
org-element--parsed-properties-alist org-element-dual-keywords 
org-element-multiple-keywords org-element-greater-elements] 11 "\n\n(fn 
--DATA)"](#("Functional Programming in Scala for Mortals" 0 43 (:parent (#0
  mapc(#[257 
"\211\211:\204\211;\205\311\262\202\211@9\205\211@\262
?\206\251\301\203-
\312\301\313\">\206\251\211\2049\314\310\242\"\202\251\211\315=\203]\314\310\242\211:\204N\316\262\202Y\211@9\203Y\211AA\262\"\202\251\211\304>\203~\300!\211\203}\302\203v\317\320\"\210\202}\307\307\242B\240\210\210\306\321=\203\271
;\204\271\211\236A\211\203\270\211@\310\242\211;\203\247\322\323#\266\202\202\257\312A@\"\266\202!\210A\266\202\202\216\210\303\203Q\306\321=\203Q\324!\325=\203Q\211\203P\211@\211@A\211;\203\347\322\323#\266\202\202\357\312A@\"\266\202\211\203G
\235\2030
\235\203!\326!\211\203
\211@\310\242A!\210\310\242@!\210A\266\202\202
\210\202G\310\242A!\210\310\242@!\210\202G
\235\203B\314\310\242\326!\"\210\202G\310\242!\210\266
A\266\202\202\315\210\211\305>\206\251
\211:\204c\316\262\202n\211@9\203n\211AA\262?\206\251\306\327=\203\200\211>?\206\251\306\330=\203\216\324!\331=\206\251\314\310\242\211:\204\235\316\262\202\250\211@9\203\250\211AA\262\"\207"
 [#[257 
"\211\305\306\307#\310\311\211:\204\312\202\"\n@9\203!\nAA\202\"\n)\"\210\313\314
  \211:\2043\312\202@\n@9\203?\nAA\202@\n)#\210\315\211 
\n;\203V\316\317\n#\202\\\320\nA@\"*\211;\203n\321\n\312\f$\202z\nA\322\nA@\f#\240\210\n+\210
 AA@\240\210@\240*\207" [new old element property value