#27360 closed enhancement (fixed)
upgrade eclib to v20190226
Reported by:  cremona  Owned by:  

Priority:  major  Milestone:  sage8.7 
Component:  packages: standard  Keywords:  eclib, upgrade 
Cc:  slelievre, fbissey, ghtimokau  Merged in:  
Authors:  John Cremona, Jeroen Demeyer  Reviewers:  Jeroen Demeyer, John Cremona 
Report Upstream:  N/A  Work issues:  
Branch:  901eaf8 (Commits)  Commit:  
Dependencies:  Stopgaps: 
Description
Release v20170815 introduced a modular symbol scaling bug (while sorting out modular symbol scaling essentially correctly) in functions not currently used by Sage. Other releases since the current one in Sage (v20180815) make some interface changes including precision handling (now using bits not digits), so some Sage code changes are likely to be necessary.
Updated source: http://homepages.warwick.ac.uk/staff/J.E.Cremona/ftp/eclib20190226.tar.bz2
Change History (77)
comment:1 Changed 12 months ago by
 Cc slelievre added
 Keywords upgrade added
comment:2 Changed 12 months ago by
comment:3 Changed 12 months ago by
The current tarball's configure script sets compiler flags which result in code requiring an optional FLINT module which Sage's FLINT does not have, which I have on my own machine and always forget to remove for Sage. I will replace it. (The module is hmod_mat which allows for linear algebra mod p using 32bit integers.)
comment:4 Changed 12 months ago by
 Cc fbissey added
comment:5 Changed 12 months ago by
 Branch set to u/cremona/eclib
 Commit set to 25d6db58591c04f90e2f3626b0ee1755d0fdaec7
 Status changed from new to needs_review
New commits:
25d6db5  #27360 eclib upgrade to v20190226

comment:6 followup: ↓ 9 Changed 12 months ago by
I did the testing on a python3 build of Sage.
comment:7 Changed 12 months ago by
Typo: procision
comment:8 Changed 12 months ago by
 Cc ghtimokau added
comment:9 in reply to: ↑ 6 ; followup: ↓ 10 Changed 12 months ago by
Replying to cremona:
I did the testing on a python3 build of Sage.
That is what I thought but it seems that the steps make distclean; make build took me back to python2 (where all is well with the patch uploaded).
I will build the branch from scratch again, this time making sure it is python3.
comment:10 in reply to: ↑ 9 Changed 12 months ago by
comment:11 Changed 12 months ago by
Thanks  I misunderstood Vincent's recent instructions on sagedevel. So now the situation is that this branch works fine under python2 but not under python3 where the output buffering issue arises. To be clear: after switching to this commit and putting the new source tarball into upstream/ I do
make distclean ./configure withpython=3 MAKE='make j20' make ./sage t src/sage/libs/eclib
and see doctest failures in 2 files all of which (by eye) are caused by output buffering.
The same happens on a different machine and a python3 build of vanilla 8.7.beta5 so this issue is *not* related to the eclib upgrade at all. For that reason it might be better to open a new ticket for it, and not hold up this one.
comment:12 Changed 12 months ago by
As a *proof* that this is the issue, after
export PYTHONUNBUFFERED=1
the test
./sage t src/sage/libs/eclib
runs fine. I suppose that we do not want to turn off all python output buffering always?
comment:13 followup: ↓ 16 Changed 12 months ago by
The last comment is surprising to me... how would disabling Python buffering fix buffering issues in eclib?
comment:14 followup: ↓ 18 Changed 12 months ago by
Minor nitpick, but why this change?
 r"""  Set the global NTL real number precision. This has a massive + r""" Set the global NTL real number bit precision. This has a massive
I don't know if it's right or wrong to format docstrings like that, but in any case this seems to go against the typical Sage docstring style. And if you really insist on starting the text on the line with the """
I would at least remove the leading space before Set the
.
comment:15 followup: ↓ 17 Changed 12 months ago by
Is DNTL_ALL
now superfluous? If so, you could remove the line
# distutils: extra_compile_args = DNTL_ALL
from src/sage/libs/eclib/__init__.pxd
comment:16 in reply to: ↑ 13 ; followup: ↓ 20 Changed 12 months ago by
Replying to jdemeyer:
The last comment is surprising to me... how would disabling Python buffering fix buffering issues in eclib?
Well if you ignore my "proof" remark it seems to be a fact that setting that environment variable fixes the issue. Nothing has changed in eclib regarding buffering.
One fix would be to make changes in the Sage interface so that whenever an eclib function is called which outputs to stdout, the python stdout is flushed first. It would be possible to add flushing functions in eclib itself but that does not seem the right approach to me.
comment:17 in reply to: ↑ 15 Changed 12 months ago by
Replying to jdemeyer:
Is
DNTL_ALL
now superfluous? If so, you could remove the line# distutils: extra_compile_args = DNTL_ALLfrom
src/sage/libs/eclib/__init__.pxd
You are right, and I will remove that line.
comment:18 in reply to: ↑ 14 Changed 12 months ago by
Replying to jdemeyer:
Minor nitpick, but why this change?
 r"""  Set the global NTL real number precision. This has a massive + r""" Set the global NTL real number bit precision. This has a massiveI don't know if it's right or wrong to format docstrings like that, but in any case this seems to go against the typical Sage docstring style. And if you really insist on starting the text on the line with the
"""
I would at least remove the leading space beforeSet the
.
Sorry that is an artefact introduced by emacs python mode which I usually change back manually. I'll do that.
comment:19 Changed 12 months ago by
 Commit changed from 25d6db58591c04f90e2f3626b0ee1755d0fdaec7 to 8c0f97697c4c751a5a12c3974366ecd8d1f1e63f
Branch pushed to git repo; I updated commit sha1. New commits:
8c0f976  #27360 changes addressing reviewer suggestions

comment:20 in reply to: ↑ 16 Changed 12 months ago by
I created #27383 for the buffering issues.
comment:21 Changed 12 months ago by
There is still procision
comment:22 Changed 12 months ago by
 Commit changed from 8c0f97697c4c751a5a12c3974366ecd8d1f1e63f to 36bf0909d81ef12a4328bd3c7afda5c23700d14a
Branch pushed to git repo; I updated commit sha1. New commits:
36bf090  fix typo

comment:23 Changed 12 months ago by
Thanks  I fixed the typo and assume that the buffering questions will be fixed in #27383.
comment:24 Changed 12 months ago by
 Reviewers set to Jeroen Demeyer
I have no more comments on the branch, now testing...
comment:25 Changed 12 months ago by
 Status changed from needs_review to needs_work
On a 32bit machine I get
sage t warnlong 43.4 src/sage/libs/eclib/mwrank.pyx ********************************************************************** File "src/sage/libs/eclib/mwrank.pyx", line 365, in sage.libs.eclib.mwrank._Curvedata.cps_bound Failed example: E.cps_bound() Expected: 0.11912451909250964 Got: 0.11912451909250982 ********************************************************************** File "src/sage/libs/eclib/mwrank.pyx", line 404, in sage.libs.eclib.mwrank._Curvedata.height_constant Failed example: E.height_constant() Expected: 0.11912451909250964 Got: 0.11912451909250982 ********************************************************************** File "src/sage/libs/eclib/mwrank.pyx", line 1344, in sage.libs.eclib.mwrank._two_descent.regulator Failed example: D2.regulator() Expected: 0.41714355875838 Got: 0.417143558758384 **********************************************************************
and
sage t warnlong 43.4 src/sage/libs/eclib/interface.py ********************************************************************** File "src/sage/libs/eclib/interface.py", line 601, in sage.libs.eclib.interface.mwrank_EllipticCurve.regulator Failed example: E.regulator() Expected: 0.051111408239969 Got: 0.05111140823996884 ********************************************************************** File "src/sage/libs/eclib/interface.py", line 1083, in sage.libs.eclib.interface.mwrank_MordellWeil.regulator Failed example: E.regulator() Expected: 0.41714355875838 Got: 0.417143558758384 **********************************************************************
comment:26 Changed 12 months ago by
Oh misery. I don't have a 32bit machine to test on. But I also have no idea why there should be any difference. I don't think I have ever before had to deal with 32/64bit issues with eclib in Sage. Sage uses NTL floating point (which used to require siwtching on with the NTL_ALL flag but now is on by default) and that is 32/64independent.
comment:27 Changed 12 months ago by
Could there be a problem with the precision handling? I made this change:

src/sage/libs/eclib/wrap.cpp
diff git a/src/sage/libs/eclib/wrap.cpp b/src/sage/libs/eclib/wrap.cpp index de70e6b..88fcebe 100644
a b char* two_descent_regulator(struct two_descent* t) 250 250 bigfloat reg = t>regulator(); 251 251 ostringstream instore; 252 252 instore << reg; 253 return stringstream_to_char(instore); 253 char *ptr = stringstream_to_char(instore); 254 printf("two_descent_regulator(): %s\n", ptr); 255 return ptr; 254 256 }
to debug the bigfloat
object t>regulator()
.
On 64bit, I get
sage: E = mwrank_EllipticCurve([0, 0, 1, 1, 0]); E.regulator() two_descent_regulator(): 0.051111408239968840235886099756942021609538202280852964249242761521097051665601926126276280166145013158726830156913137573334269246681032033729207105828 0.05111140823996884
On 32bit, I get
sage: E = mwrank_EllipticCurve([0, 0, 1, 1, 0]); E.regulator() two_descent_regulator(): 0.0511114082399688402358860997569420216095382 0.05111140823996884
comment:28 Changed 12 months ago by
I applied this patch to debug:

src/sage/libs/eclib/wrap.cpp
diff git a/src/sage/libs/eclib/wrap.cpp b/src/sage/libs/eclib/wrap.cpp index de70e6b..74d92a4 100644
a b char* two_descent_regulator(struct two_descent* t) 250 250 bigfloat reg = t>regulator(); 251 251 ostringstream instore; 252 252 instore << reg; 253 return stringstream_to_char(instore); 253 char *ptr = stringstream_to_char(instore); 254 printf("two_descent_regulator():\n%s\nprecision = %ld\nas double = %a\n", ptr, reg.precision(), to_double(reg)); 255 return ptr; 254 256 }
What I see when I run the doctests on 64bit:
sage t src/sage/libs/eclib/interface.py ********************************************************************** File "src/sage/libs/eclib/interface.py", line 601, in sage.libs.eclib.interface.mwrank_EllipticCurve.regulator Failed example: E.regulator() Expected: 0.051111408239969 Got: two_descent_regulator(): 0.051111408239969 precision = 53 as double = 0x1.a2b4645afb41dp5 0.051111408239969 **********************************************************************
So the precision is only 53 bits here. So one of the tests preceding it apparently changes the precision from 150 to 53.
comment:29 followup: ↓ 31 Changed 12 months ago by
Another obvious thing to ask is why does the eclib interface uses strings for conversion? For the regulator, an NTL RR
is converted to a string and then to a Python float
. It would be more efficient and more reliable to use the NTL conversion function to_double
.
comment:30 followup: ↓ 32 Changed 12 months ago by
The problem is obvious: you have a doctest sage: mwrank_set_precision(50)
which means that all following doctests are run with a precision much lower than default.
comment:31 in reply to: ↑ 29 Changed 12 months ago by
Replying to jdemeyer:
Another obvious thing to ask is why does the eclib interface uses strings for conversion? For the regulator, an NTL
RR
is converted to a string and then to a Pythonfloat
. It would be more efficient and more reliable to use the NTL conversion functionto_double
.
I agree. I didn't write the wrapping code  I have only tweaked it so take changes to eclib into account.
Do you know how to convert an NTL RR into an element of RealField?() or some other Sage real type?
(Edit: I don't think that it would fix the doctest failures, it's just something that I saw while reading the code)
comment:32 in reply to: ↑ 30 Changed 12 months ago by
Replying to jdemeyer:
The problem is obvious: you have a doctest
sage: mwrank_set_precision(50)
which means that all following doctests are run with a precision much lower than default.
Of course, how stupid. This hardly needs a doctest; it would be silly to use the default here; perhaps the doctest should be expanded to save the current precision, set it to a new value and then rest it. I will do that.
comment:33 Changed 12 months ago by
@jdemeyer: after editing the file wrap.cpp what exactly needs to be done to rebuild sage? I have the impression that neither "sage b" nor "make" caused that file to be recompiled when it changed.
comment:34 followup: ↓ 35 Changed 12 months ago by
Yes, I noticed that too and created a new ticket #27389. To solve this problem concretely, remove all copies of wrap.cpp
in the src/build
directory and try again.
comment:35 in reply to: ↑ 34 Changed 12 months ago by
comment:36 Changed 12 months ago by
 Commit changed from 36bf0909d81ef12a4328bd3c7afda5c23700d14a to d63916a12d7fbc038ed7c6fb2fa4eadbd8fa64a6
Branch pushed to git repo; I updated commit sha1. New commits:
d63916a  #27360: fix flushing, avoid some stringy interfaces

comment:37 followup: ↓ 39 Changed 12 months ago by
 Status changed from needs_work to needs_review
The latest commit d63916a address some of the issues discovered.
 By adding a couple of "cou<<flush;" statememts in the c++ wrapper file wrap.cpp I think I have dealt with that problem under python3. At the same time I deleted some flushing which was there already but redundant. The result works fine in python3.
 Fixed an interface bug where I called eclib's set_precision() instead of set_bit_precision. The former still takes a decimal precision input.
 Fixed a doctesting bug where one test left the preciaion at a different value than the usual default.
 Avoid converting an NTL:RR to a float via strings by using iNTL's to_double() as suggested, returning a double.
All that left a lot of computed number ending in some different digits. I fixed those doctests in the stupid way, i.e. changing the expected digits to what I now get. But I only tested on a 64bit machine. If there are problems on 32bit I will probably get around that by replacing some trailing digits by "...".
Putting this back to "needs review", and the testing and debugging help already received are much appreciated.
comment:38 Changed 12 months ago by
There is still a mwrank_set_precision(50)
doctest in src/sage/libs/eclib/interface.py
, shouldn't that be fixed too?
comment:39 in reply to: ↑ 37 Changed 12 months ago by
comment:40 Changed 12 months ago by
Speaking of getting/setting precision, I wonder why there are get_precision
and set_precision
functions in both src/sage/libs/eclib/mwrank.pyx
and src/sage/libs/eclib/interface.py
. There is probably a historical reason for this, but it's confusing.
I suggest to remove the get_precision
and set_precision
functions from src/sage/libs/eclib/interface.py
and then adjust the imports in src/sage/libs/eclib/all.py
.
Note that the docstring for these functions in src/sage/libs/eclib/mwrank.pyx
and src/sage/libs/eclib/interface.py
are different, so they should be merged.
comment:41 Changed 12 months ago by
 Status changed from needs_review to needs_work
comment:42 followup: ↓ 43 Changed 12 months ago by
I'll fix this.
comment:43 in reply to: ↑ 42 Changed 12 months ago by
Replying to jdemeyer:
I'll fix this.
Thanks  but I also could do it.
The eclib wrapping happened in 2007 or 2006, by William I made many changes to eclib at the time to make an interface even possible, but did not do the wrapping as at that time I had never written a single line of python. After that William often suggested that it needed to be redone from scratch but the intersection of people who had the expertise to do that was always empty.
comment:44 Changed 12 months ago by
 Branch changed from u/cremona/eclib to u/jdemeyer/eclib
comment:45 Changed 12 months ago by
 Commit changed from d63916a12d7fbc038ed7c6fb2fa4eadbd8fa64a6 to 29b22888066867ec53bef6ab3c3f5fa840e93837
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
72f217b  #27360 eclib upgrade to v20190226

2defe8a  #27360: fix flushing, avoid some stringy interfaces

69d2f64  Allow any kind of iterable for ainvs

ff2e9dd  Remove get/set_precision from eclib/interface.py

17635d8  Do not import eclib at startup

29b2288  Remove superfluous "cdef double" declarations

comment:46 Changed 12 months ago by
Rebased to 8.7.beta6 and partially squashed. The last 4 commits are by me and fix various minor things. Each of these commits is more or less independent.
comment:47 Changed 12 months ago by
 Dependencies set to #27389
comment:48 followup: ↓ 49 Changed 12 months ago by
Thanks. The diffs look good and I will do my own testing once the rebuild is done. As soon as we are both happy I think we can set this to Positive Review though I do not know what the strange colour of the patchbot icon means.
comment:49 in reply to: ↑ 48 Changed 12 months ago by
Replying to cremona:
I do not know what the strange colour of the patchbot icon means.
That it's a package upgrade and the patchbot doesn't (or can't) know how to deal with those.
comment:50 Changed 12 months ago by
 Status changed from needs_work to needs_review
This passes all tests in src/sage/libs/eclib/
and src/sage/schemes/elliptic_curves/
both on 32bit and 64bit Linux.
comment:51 Changed 12 months ago by
 Reviewers changed from Jeroen Demeyer to Jeroen Demeyer, John Cremona
comment:52 Changed 12 months ago by
When I test this on a python3 build, then there are some doctest failures in elliptic_curves most of which are unrelated unresolved python3 things, except perhaps one in height.py:
File "src/sage/schemes/elliptic_curves/height.py", line 1934, in sage.schemes.elliptic_curves.height.EllipticCurveCanonicalHeight.min_gr Failed example: H.min_gr(.1,5,True) # long time (~22s) Expected: B_1(1) = 1540.199246369678 ... halving mu to 0.25 and increasing n_max to 6 ... halving mu to 0.001953125 and increasing n_max to 13 doubling mu to 0.0078125 doubling mu to 0.015625 height bound in [0.0078125, 0.015625] using n_max = 13 ... height bound in [0.0120485220735, 0.0131390064883] using n_max = 13 0.012048522073499539 Got: B_1(1) = 1540.199246369678 B_2(1) = 621360.723701339 B_3(1) = 13686380726.84389 B_4(1) = 1.6459300096812694e+16 B_5(1) = 4.322868545515137e+22 halving mu to 0.25 and increasing n_max to 6 halving mu to 0.125 and increasing n_max to 7 halving mu to 0.0625 and increasing n_max to 8 halving mu to 0.03125 and increasing n_max to 9 halving mu to 0.015625 and increasing n_max to 10 halving mu to 0.0078125 and increasing n_max to 11 halving mu to 0.00390625 and increasing n_max to 12 halving mu to 0.001953125 and increasing n_max to 13 doubling mu to 0.0078125 doubling mu to 0.015625 height bound in [0.0078125, 0.015625] using n_max = 13 height bound in [0.011048543456039806, 0.015625000000000003] using n_max = 13 height bound in [0.011048543456039806, 0.01313900648833929] using n_max = 13 height bound in [0.012048522073499539, 0.01313900648833929] using n_max = 13 0.012048522073499539 **********************************************************************
where the penultimate line (only) is slightly different. Did that test really pass for you?
comment:53 followup: ↓ 54 Changed 12 months ago by
I tested Python 2, not Python 3. Did you test both Python 2 and Python 3 or only Python 3?
I would find it quite surprising that you get different numerical noise on Python 3 compared to Python 2. More likely, it depends on the machine and not on the Python version.
comment:54 in reply to: ↑ 53 Changed 12 months ago by
Replying to jdemeyer:
I tested Python 2, not Python 3. Did you test both Python 2 and Python 3 or only Python 3?
Only Python 3
I would find it quite surprising that you get different numerical noise on Python 3 compared to Python 2. More likely, it depends on the machine and not on the Python version.
Me too. The only numerical computation with output other than halving or doubling is line 1975 of height.py where math.sqrt() is used on a float. Perhaps mu and eps should be in RDF from the start, as the output is coerced in there at the end. But this does not explain the discrepancy, it must be a machine difference.
comment:55 Changed 11 months ago by
 Dependencies #27389 deleted
comment:56 Changed 11 months ago by
 Commit changed from 29b22888066867ec53bef6ab3c3f5fa840e93837 to 3ff19c1e0180ed48e85cda56d3899ae082013c1c
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
0e3efa2  #27360 eclib upgrade to v20190226

424678c  #27360: fix flushing, avoid some stringy interfaces

dc98893  Allow any kind of iterable for ainvs

00754ba  Remove get/set_precision from eclib/interface.py

c2fcfc3  Do not import eclib at startup

3ff19c1  Remove superfluous "cdef double" declarations

comment:57 Changed 11 months ago by
I tested this again (on x86_64 laptop with Sage 8.7.beta7 under Python 2) and all long tests in src/sage/schemes/elliptic_curves/
do pass for me.
comment:58 Changed 11 months ago by
 Commit changed from 3ff19c1e0180ed48e85cda56d3899ae082013c1c to 8936611b538c6e8bbd192c224828a5c2a9424be6
Branch pushed to git repo; I updated commit sha1. New commits:
8936611  Numerical noise

comment:59 Changed 11 months ago by
This should work now.
comment:60 followup: ↓ 61 Changed 11 months ago by
What is the difference between the commits in comment 56 and those in comment 45?
comment:61 in reply to: ↑ 60 Changed 11 months ago by
comment:62 Changed 11 months ago by
So should I rebuild my python3 using your rebase and test again what I saw at comment 53? Or should we leave this to be dealt with later when other python3 issues are finally fixed?
comment:63 Changed 11 months ago by
I built and tested this on Python 3 myself. I can indeed reproduce the failure from 52. I'll try to figure out why it's happening, if only because I'm honestly curious.
comment:64 Changed 11 months ago by
 Status changed from needs_review to needs_work
OK, the difference between Python 2 and 3 is that the same numbers are printed differently. So this suggests a different fix: use %r
which always print floats exactly.
comment:65 Changed 11 months ago by
 Commit changed from 8936611b538c6e8bbd192c224828a5c2a9424be6 to 901eaf8760dc96dac0fc3757fc5f90ddf1cf850c
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
901eaf8  Print numbers consistently on Python 2 and 3

comment:66 Changed 11 months ago by
Well spotted, and thanks for fixing. I'm still building the previous version but will continue.
comment:67 Changed 11 months ago by
I made a few more minor fixes in that function, in particular replacing /= 2
by *= 0.5
(dividing an integer by an integer has different semantics in Python 3, so this might fix a not yet discovered Python 3 bug). I could have written /= 2.0
but decided that the multiplication would be faster too (not that it matters here).
comment:68 Changed 11 months ago by
 Status changed from needs_work to needs_review
comment:69 Changed 11 months ago by
When I pull your commit 901eaf8 on top of 8936611 I get a merge conflict in height.py. That seems to be because the parent of your latest commit is not 8936611 but 3ff16c1. Did you mean to get rid of commit 8936611?
comment:70 followup: ↓ 71 Changed 11 months ago by
Don't pull. Just checkout my branch.
comment:71 in reply to: ↑ 70 ; followup: ↓ 73 Changed 11 months ago by
Replying to jdemeyer:
Don't pull. Just checkout my branch.
Of course. For some reason I had created a new branch tracking trac/u/jdemeyer/eclib. Still, I think it may be bad practice to upload a branch with same name as an old one but which does not have the old one as parent...
comment:72 Changed 11 months ago by
 Status changed from needs_review to positive_review
OK, so testing all the elliptic_curves directory with a python3 build the only failures I get are ones which have nothing to do with this fix.
For the record there is one failure in each of ell_rational_field, ell_number_field, and padic_lseries. The one in ell_rational_field has been fixed in #27432.
comment:73 in reply to: ↑ 71 ; followup: ↓ 74 Changed 11 months ago by
Replying to cremona:
Still, I think it may be bad practice to upload a branch with same name as an old one but which does not have the old one as parent...
I think you're right in principle. On the other hand, sometimes it is more practical to just rebase a branch. For example, having one commit and then another one which reverts that is just adding noise to the git history. In that case, I'd rather just remove the commit.
comment:74 in reply to: ↑ 73 Changed 11 months ago by
Replying to jdemeyer:
Replying to cremona:
Still, I think it may be bad practice to upload a branch with same name as an old one but which does not have the old one as parent...
I think you're right in principle. On the other hand, sometimes it is more practical to just rebase a branch. For example, having one commit and then another one which reverts that is just adding noise to the git history. In that case, I'd rather just remove the commit.
*and* as a courtesy to others, add a comment on trac to say that that is what you have done!
comment:75 Changed 11 months ago by
 Branch changed from u/jdemeyer/eclib to 901eaf8760dc96dac0fc3757fc5f90ddf1cf850c
 Resolution set to fixed
 Status changed from positive_review to closed
comment:76 Changed 11 months ago by
 Commit 901eaf8760dc96dac0fc3757fc5f90ddf1cf850c deleted
Good news! This ticket took a bit longer than expected...
comment:77 Changed 11 months ago by
I would like to publicly thank Jeroen for his work on this. It's not the first time that eclib's inclusion in Sage has led to improvements in the library itself.
The less good news is that some of my code it not converging well with the new precision handling (decimal to bits) but not in a part which affects Sage, so there will not be another ticket to upgrade again. Well, not this month.
Thanks for adding the new keyword. I have built 8.7.beta5 and am starting to test.