fpylll might not find system-wide fplll's strategies json

[dimpase]

This in particular is observed on Debian 11, see
fplll/fpylll#221

sage: from sage.modules.free_module_integer import IntegerLattice
sage: L = IntegerLattice(sage.crypto.gen_lattice(type='modular', m=10, seed=1337, dual=True))
sage: L.shortest_vector()
terminate called after throwing an instance of 'std::runtime_error'
  what():  Cannot open strategies file.
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
~/work/sage/local/var/lib/sage/venv-python3.9/lib/python3.9/site-packages/sage/misc/cachefunc.pyx in sage.misc.cachefunc.CachedMethodCaller.__call__ (build/cythonized/sage/misc/cachefunc.c:10347)()
   1942             try:
-> 1943                 return cache[k]
   1944             except TypeError:  # k is not hashable

KeyError: ((True, 'fplll'), ())
...

The latter is an extract from a failing doctest.

While it's fixed in fplll's master, we need a fix for the current fpylll.

Upstream: Fixed upstream, in a later stable release.

Component: packages: standard

Author: Dima Pasechnik

Branch: 20ca9f7

Reviewer: Martin Albrecht

Issue created by migration from https://trac.sagemath.org/ticket/33302

[malb]

comment:1

I think it should be enough to update FPLLL to fix this, no? I can cut a new release (for both).

[dimpase]

comment:2

We are allowing system-wide versions of fplll. I.e. we are stuck with this little bug for some time.

[dimpase]

Branch: u/dimpase/fpylll/stategies_path_fix

[dimpase]

Upstream: Fixed upstream, in a later stable release.

[dimpase]

Author: Dima Pasechnik

[dimpase]

Commit: 20ca9f7

[dimpase]

New commits:

20ca9f7

compose the path to strategies/default.json

[malb]

Reviewer: Martin Albrecht

[malb]

comment:4

I am a bit puzzled how this situation can arise but the fix doesn't make it wrong, so thumbs up from me. I didn't run doctests, though.

[dimpase]

comment:5

Replying to @malb:

I am a bit puzzled how this situation can arise but the fix doesn't make it wrong, so thumbs up from me. I didn't run doctests, though.

Thanks. On Debian 11 BKZ.DEFAULT_STRATEGY is not full path, it's just default.json. So the path has to be prepended.
In some other cases it's full path, so either nothing should be prepended, or it can be done as in the patch.

[vbraun]

Changed branch from u/dimpase/fpylll/stategies_path_fix to 20ca9f7

[mkoeppe]

Changed commit from 20ca9f7 to none

[mkoeppe]

comment:7

Again on opensuse-tumbleweed - #33448