build script tries to install NTL in /usr/local/include/NTL

[heiderich]

When executing Pkg.build("Singular"), the build script seems to try to install NTL under /usr/local/include/NTL, which usually fails when executed as a non-privileged user.

make[1]: Leaving directory '/home/florian/.julia/v0.6/Singular/deps/tmpEConDD/ntl-9.3.0/src'
touch all
mkdir -p -m 755 /usr/local/include
rm -rf /usr/local/include/NTL
mkdir -m 755 /usr/local/include/NTL
mkdir: cannot create directory ‘/usr/local/include/NTL’: Permission denied
makefile:427: recipe for target 'install' failed
make: *** [install] Error 1
===============================================[ ERROR: Singular ]================================================

LoadError: failed process: Process(`make install`, ProcessExited(2)) [2]
while loading /home/florian/.julia/v0.6/Singular/deps/build.jl, in expression starting on line 30

==================================================================================================================

=================================================[ BUILD ERRORS ]=================================================

WARNING: Singular had build errors.

 - packages with build errors remain installed in /home/florian/.julia/v0.6
 - build the package(s) and all dependencies with `Pkg.build("Singular")`
 - build a single package by running its `deps/build.jl` script

==================================================================================================================

[wbhart]

That's interesting. We do configure NTL with: run(`./configure PREFIX=$vdir DEF_PREFIX=$nemovdir .....`) and certainly neither of those directories is /usr/local/include/NTL. I'm not sure what is causing this issue. Perhaps we are issuing the configure command to NTL incorrectly.

[sebasguts]

According to the comments in NTL's configure script, this seems the right way to use it. Nevertheless, the PREFIX variable is ignored.

[wbhart]

I wonder if it is fixed in a later version of NTL, and if such a version will work with Singular. Otherwise, we might need to apply a patch. I wonder if this could explain some of the difficulties we've had on OSX (I realise it shouldn't work on Linux either, but maybe we've just been lucky).

[sebasguts]

This does not explain any of the difficulties I had on OS X, sorry. And this problem occurs on a Linux machine.

Singular itself works with newer versions of NTL, but I am not sure if this problem is fixed there.

[sebasguts]

TBH, I encountered this problem before, but was too lazy to dig into it. This is why I put the sudo here: https://github.com/oscar-system/OSCARDocker/blob/master/Dockerfile#L67 .

Should I investigate this?

[wbhart]

If you have time, that would be great. Of course, adding sudo is not a way around it in general. Most users wouldn't have sudo access to their machines. But it's understandable why one would do it in a Docker image.

[sebasguts]

It basically solved it back then without much hassle for me, so I was fine with doing it in the image. I will investigate this.

[sebasguts]

So, after investigating this, I found the following explanation:

For correctly executing the configure script of ntl, you need a libtool binary in your path. This comes with the Ubuntu/Debian package libtool-bin, and not libtool. If you do not have that binary in your path, ntl's configure errors and does not overwrite ntl's already existing makefile.

Then the build.jl still executes make (which runs fine), and you get an error when build.jl tries to make install ntl.

I guess we should at least try/catch the configure call and see if configure was executed successfully. And then possibly provide a more elaborated error than ntl does by itself. I will implement this.

[heiderich]

Thank you for investigating this @sebasguts. After installing libtool-bin I could build this package successfully.

[fingolfin]

This issue was fixed in NTL 10.1.0, released 2016-10-14 -- perhaps you could switch from NTL 9.3.0 to that, or an even newer version of NTL?