better error-handling when talking to remote server

[umlaeute]

I started FaustLive, clicked randomly on one of the examples (unfortunately i don't remember which one), went to export as... (Ctrl+P), picked some linux target (again, i don't really remember which one), and the export manager started.

After giving me a green :heavy_check_mark: for "connection to server", the "remote compilation" step failed with a red :x: and the following error:

Error downloading http://faustservice.grame.fr/%3Chtml%3E%3Cbody%3E%3Cp%3EThe%20upload%20is%20completed%20but%20the%20file%20you%20uploaded%20is%20not%20a%20valid%20Faust%20file.%20%20%20Make%20sure%20that%20it%20is%20either%20a%20file%20with%20an%20extension%20.dsp%20or%20an%20archive%20(tar.gz,%20tar.bz,%20tar%20%20%20or%20zip)%20containing%20one%20.dsp%20file%20and%20potentially%20.lib%20files%20included%20by%20the%20.dsp%20file.%20%20%20Furthermore,%20the%20code%20in%20these%20files%20must%20be%20valid%20Faust%20code.%3C/p%3E%20%20%20%3Cp%3EBelow%20is%20the%20STDOUT%20and%20STDERR%20for%20the%20Faust%20code%20you%20tried%20to%20compile.%20%20%20If%20the%20two%20are%20empty,%20then%20your%20file%20structure%20is%20wrong.%20Otherwise,%20they%20will%20tell%20you%20%20%20why%20Faust%20failed.%3C/p%3EERROR%20:%20path%20'/CONSTANT-Q_FILTER_BANK_(Butterworth_dyadic_tree)/0x00/0x00'%20is%20already%20used%0A%3C/body%3E%3C/html%3E/linux/jack-console-64bits/binary.zip - server replied: Not Found

I would have expected the decoded error-string to be displayed:

The upload is completed but the file you uploaded is not a valid Faust file. Make sure that it is either a file with an extension .dsp or an archive (tar.gz, tar.bz, tar or zip) containing one .dsp file and potentially .lib files included by the .dsp file. Furthermore, the code in these files must be valid Faust code.

Below is the STDOUT and STDERR for the Faust code you tried to compile. If the two are empty, then your file structure is wrong. Otherwise, they will tell you why Faust failed.

ERROR : path '/CONSTANT-Q_FILTERBANK(Butterworth_dyadic_tree)/0x00/0x00' is already used

[sletz]

Known problem.

Some FL included examples do no compile anymore because the remote compiler is more restrictive. The examples have been fixed in the main Faust repository and will be update dat next FL build and release.

[umlaeute]

i think there will always be reasons for problems. that's the nature of a complex piece of software.

i'm mainly arguing that the error-message as presented to the user could be more, well, user-friendly (that is: don't show HTML-encoded text)