[LV2] Ardour doesn't find lv2

[rosea.grammostola]

On 12/12/2012 02:27 AM, David Robillard wrote:
> On Wed, 2012-12-12 at 01:11 +0100, rosea.grammostola wrote:
>> On 12/12/2012 12:00 AM, David Robillard wrote:
>>> On Tue, 2012-12-11 at 23:41 +0100, rosea.grammostola wrote:
>>> [...]
>>>> Anyway, if I do
>>>> echo $LV2_PATH
>>>>
>>>> I get an empty line
>>>
>>> There is a big difference between an environment variable being set to
>>> the empty string, and the environment variable not being set at all.
>>> Both will print nothing for this command.  As I mentioned earlier,
>>> 'export' will print all set environment variables.
>>>
>>> Perhaps yours has been set to the empty string?  This will result in
>>> zero plugins.  You can use 'unset LV2_PATH' to unset it.
>>>
>>>> If I do
>>>> LV2_PATH=/usr/lib/lv2
>>>> lv2ls works (but only in the terminal in which I set the path)
>>>>
>>>> lv2ls contains some weird files
>>> [snip]
>>>
>>> All valid URIs, this looks fine.
>>>
>>> -dr
>>
>> This also?
>>
>> ~$ lv2ls
>> file:///usr/lib/lv2/StereoInOut.ingen/StereoInOut.ttl
>> http://studionumbersix.com/foo/lv2/yc20
>> urn:50m30n3:plugins:SO-404
>> urn:50m30n3:plugins:SO-666
>> urn:50m30n3:plugins:SO-kl5
>> urn:juce:TalDub3
>> urn:juce:TalFilter
>> urn:juce:TalFilter2
>> urn:juce:TalReverb
>> urn:juce:TalReverb2
>> urn:juce:TalReverb3
>
> Yes.  There is no rule that URIs have to be HTTP URIs or anything like
> that.  Any valid URI will do, though I certainly don't think using URNs
> for plugins is a very good idea, it's not invalid.
>
> The first is an Ingen patch.  As it happens, an Ingen patch saved
> anywhere is inherently an LV2 plugin.  If you save to ~/.lv2 it will
> show up automatically in hosts.  Not a long-term stable or portable URI,
> but it is convenient sometimes.
>
>> export
>> declare -x LV2_PATH=""
>
> That's your problem.  An empty path contains no plugins.
>
> Please let me know how it got this way when you figure it out.  I could
> make lilv interpret the empty string as unset, though this would make it
> impossible to completely disable the path, which might not be good.  I
> don't know any precedent here, but I'm hesitant to remove power to work
> around what seems like an rather uncommon PEBKAC.
>
If I do

export LV2_PATH=~/.lv2:/usr/lib/lv2:/usr/local/lib/lv2

Then everything works normal for *that terminal/xterm*

If I do export in an other terminal I get still
declare -x LV2_PATH=""