We are happy to announce the release of Spot 2.2.2.
This is a maintenance release that only contains minor bug fixes, as
listed below.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.2.2.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.2.2 (2016-12-16)
Build:
* If the system has an installed libltdl library, use it instead of
the one we distribute.
Bug fixes:
* scc_filter() had a left-over print statement that would print
"names" when copying the name of the states.
* is_terminal() should reject automata that have accepting
transitions going into rejecting SCCs. The whole point of
being a terminal automaton is that reaching an accepting
transition guarantees that any suffix will be accepted.
* The HOA parser incorrectly read "Acceptance: 1 Bar(0)" as a valid
way to specify "Acceptance: 1 Fin(0)" because it assumed that
everything that was not Inf was Fin. These errors are now
diagnosed.
* Some of the installed headers (spot/misc/fixpool.hh,
spot/misc/mspool.hh, spot/twaalgos/emptiness_stats.hh) were not
self-contained.
* ltlfilt --from-ltlf should ensure that "alive" holds initially in
order to reject empty traces.
* the on-line translator had a bug where a long ltl3ba process would
continue running even after the script had timeout'ed.
--
Alexandre Duret-Lutz
We are ashamed to announce the release of Spot 2.2.1.
This release contains only one bug fix, for a segfault that was
introduced in Spot 2.2. Many thanks to Tomáš Babiak for the report.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.2.1.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.2.1 (2016-11-21)
Bug fix:
* The bdd_noderesize() function, as modified in 2.2, would always
crash.
We are happy to announce the release of Spot 2.2.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.2.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
Spot 2.2 fixes some serious bugs and adds an assortments of small
improvements. These changes have been contributed by Alexandre
Gbaguidi Aisse, Étienne Renault, and myself. A detailed list of what
is new is given below.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.2 (2016-11-14)
Command-line tools:
* ltlfilt has a new option --from-ltlf to help reducing LTLf (i.e.,
LTL over finite words) model checking to LTL model checking. This
is based on a transformation by De Giacomo & Vardi (IJCAI'13).
* "ltldo --stats=%R", which used to display the serial number of the
formula processed, was renamed to "ltldo --stats=%#" to free %R
for the following feature.
* autfilt, dstar2tgba, ltl2tgba, ltlcross, ltldo learned to measure
cpu-time (as opposed to wall-time) using --stats=%R. User or
system time, for children or parent, can be measured separately by
adding additional %[LETTER]R options. The difference between %r
(wall-clock time) and %R (CPU time) can also be used to detect
unreliable measurements. See
https://spot.lrde.epita.fr/oaut.html#timing
Library:
* from_ltlf() is a new function implementing the --from-ltlf
transformation described above.
* is_unambiguous() was rewritten in a more efficient way.
* scc_info learned to determine the acceptance of simple SCCs made
of a single self-loop without resorting to remove_fin() for complex
acceptance conditions.
* remove_fin() has been improved to better deal with automata with
"unclean" acceptance, i.e., acceptance sets that are declared but
not used. In particular, this helps scc_info to be more efficient
at deciding the acceptance of SCCs in presence of Fin acceptance.
* Simulation-based reductions now implement just bisimulation-based
reductions on deterministic automata, to save time. As an example,
this halves the run time of
genltl --rv-counter=10 | ltl2tgba
* scc_filter() learned to preserve state names and highlighted states.
* The BuDDy library has been slightly optimized: the initial setup
of the unicity table can now be vectorized by GCC, and all calls
to setjmp are now avoided when variable reordering is disabled
(the default).
* The twa class has three new methods:
aut->intersects(other)
aut->intersecting_run(other)
aut->intersecting_word(other)
currently these are just convenient wrappers around
!otf_product(aut, other)->is_empty()
otf_product(aut, other)->accepting_run()->project(aut)
otf_product(aut, other)->accepting_word()
with any Fin-acceptance removal performed before the product.
However the plan is to implement these more efficiently in the
future.
Bugs:
* ltl2tgba was always using the highest settings for the LTL
simplifier, ignoring the --low and --medium options. Now
genltl --go-theta=12 | ltl2tgba --low --any
is instantaneous as it should be.
* The int-vector compression code could encode 6 and 22 in the
same way, causing inevitable issues in our LTSmin interface.
(This affects tests/ltsmin/modelcheck with option -z, not -Z.)
* str_sere() and str_utf8_sere() were not returning the same
string that print_sere() and print_utf8_sere() would print.
* Running the LTL parser in debug mode would crash.
* tgba_determinize() could produce incorrect deterministic automata
when run with use_simulation=true (the default) on non-simplified
automata.
* When the automaton_stream_parser reads an automaton from an
already opened file descriptor, it will not close the file
anymore. Before that the spot.automata() python function used to
close a file descriptor twice when reading from a pipe, and this
led to crashes of the 0MQ library used by Jupyter, killing the
Python kernel.
* remove_fin() could produce incorrect result on incomplete
automata tagged as weak and deterministic.
* calling set_acceptance() several times on an automaton could
result in unexpected behaviors, because set_acceptance(0,...)
used to set the state-based acceptance flag automatically.
* Some buffering issue caused syntax errors to be displayed out
of place by the on-line translator.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.1.2.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.1.2.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
Spot 2.1.2 contains a handful of bug fixes and a couple of minor
improvements, as listed below. These changes were contributed by
Étienne Renault, Alexandre Gbaguidi Aïsse, and myself.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.1.2 (2014-10-14)
Command-line tools:
* genltl learned 5 new families of formulas
(--tv-f1, --tv-f2, --tv-g1, --tv-g2, --tv-uu)
defined in Tabakov & Vardi's RV'10 paper.
* ltlcross's --csv and --json output was changed to not include
information about the ambiguity or strength of the automata by
default. Computing those can be costly and not needed by
every user, so it should now be requested explicitely using
options --strength and --ambiguous.
Library:
* New LTL simplification rule:
- GF(f & q) = G(F(f) & q) if q is
purely universal and a pure eventuality. In particular
GF(f & GF(g)) now ultimately simplifies to G(F(f) & F(g)).
Bug fixes:
* Fix spurious uninitialized read reported by valgrind when
is_Kleene_star() is compiled by clang++.
* Using "ltlfilt some-large-file --some-costly-filter" could take
to a lot of time before displaying the first results, because the
output of ltlfilt is buffered: the buffer had to fill up before
being flushed. The issue did not manifest when the input is
standard input, because of the C++ feature that reading std::cin
should flush std::cout; however it was well visible when reading
from files. Flushing is now done more regularly.
* Fix compilation warnings when -Wimplicit-fallthrough it enabled.
* Fix python errors on Darwin when using methods from the spot module
inside of the spot.ltsmin submodule.
* Fix ltlcross crash when combining --no-check with --verbose.
* Adjust paths and options used in bench/dtgbasat/ to match the
changes introduced in Spot 2.0.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.1.1.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.1.1.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
Spot 2.1.1 contains some very minor fixups, and a few command-line
improvements that should really have been part of 2.1.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.1.1 (2016-09-20)
Command-line tools:
* ltlfilt, randltl, genltl, and ltlgrind learned to display the size
(%s), Boolean size (%b), and number of atomic propositions (%a)
with the --format and --output options. A typical use-case is to
sort formulas by size:
genltl --dac --format='%s,%f' | sort -n | cut -d, -f2
or to group formulas by number of atomic propositions:
genltl --dac --output='ap-%a.ltl'
* autfilt --stats learned the missing %D, %N, %P, and %W sequences,
to complete the existing %d, %n, %p, and %w.
* The --stats %c option of ltl2tgba, autfilt, ltldo, and dstar2tgba
now accepts options to filter the SCCs to count. For instance
--stats='%[awT]c' will count the SCCs that are (a)ccepting and
(w)eak, but (not t)erminal. See --help for all supported filters.
Bugs fixed:
* Fix several cases where command-line tools would fail to diagnose
write errors (e.g. when writing to a filesystem that is full).
* Typos in genltl --help and in the man page spot-x(7).
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.1.
Spot 2.1 is mainly a collection of small improvements that have
accumulated since the release of Spot 2.0 four months ago. A
detailed list of those is given below.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.1.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
As always, please direct any feedback to <spot(a)lrde.epita.fr>.
New in spot 2.1 (2016-08-08)
Command-line tools:
* All tools that input formulas or automata (i.e., autfilt,
dstar2tgba, ltl2tgba, ltl2tgta, ltlcross, ltldo, ltlfilt,
ltlgrind) now have a more homogeneous handling of the default
input.
- If no formula/automaton have been specified, and the standard
input is a not a tty, then the default is to read that. This is a
change for ltl2tgba and ltl2tgta. In particular, it simplifies
genltl --dac | ltl2tgba -F- | autfilt ...
into
genltl --dac | ltl2tgba | autfilt ...
- If standard input is a tty and no other input has been
specified, then an error message is printed. This is a change for
autfilt, dstar2tgba, ltlcross, ltldo, ltlfilt, ltlgrind, that used
to expect the user to type formula or automata at the terminal,
confusing people.
- All tools now accept - as a shorthand for -F-, to force reading
input from the standard input (regardless of whether it is a tty
or not). This is a change for ltl2tgba, ltl2tgta, ltlcross, and
ltldo.
* ltldo has a new option --errors=... to specify how to deal
with errors from executed tools.
* ltlcross and ltldo learned to bypass the shell when executing
simple commands (with support for single or double-quoted
arguments, and redirection of stdin and stdout, but nothing more).
* ltlcross and ltldo learned a new syntax to specify that an input
formula should be written in some given syntax after rewriting
some operators away. For instance the defaults arguments passed
to ltl2dstar have been changed from
--output-format=hoa %L %O
into
--output-format=hoa %[WM]L %O
where [WM] specifies that operators W and M should be rewritten
away. As a consequence running
ltldo ltl2dstar -f 'a M b'
will now work and call ltl2dstar on the equivalent formula
'b U (a & b)' instead. The operators that can be listed between
brackets are the same as those of ltlfilt --unabbreviate option.
* ltlcross learned to show some counterexamples when diagnosing
failures of cross-comparison checks against random state spaces.
* autfilt learned to filter automata by count of SCCs (--sccs=RANGE)
or by type of SCCs (--accepting-sccs=RANGE,
--rejecting-sccs=RANGE, trivial-sccs=RANGE, --terminal-sccs=RANGE,
--weak-sccs=RANGE, --inherently-weak-sccs=RANGE).
* autfilt learned --remove-unused-ap to remove atomic propositions
that are declared in the input automaton, but not actually used.
This of course makes sense only for input/output formats that
declare atomic propositions (HOA & DSTAR).
* autfilt learned two options to filter automata by count of used or
unused atomic propositions: --used-ap=RANGE --unused-ap=RANGE.
These differ from --ap=RANGE that only consider *declared* atomic
propositions, regardless of whether they are actually used.
* autfilt learned to filter automata by count of nondeterministsic
states with --nondet-states=RANGE.
* autfilt learned to filter automata representing stutter-invariant
properties with --is-stutter-invariant.
* autfilt learned two new options to highlight non-determinism:
--highlight-nondet-states=NUM and --highlight-nondet-states=NUM
where NUM is a color number. Additionally --highlight-nondet=NUM is
a shorthand for using the two.
* autfilt learned to highlight a run matching a given word using the
--highlight-word=[NUM,]WORD option. However currently this only
work on automata with Fin-less acceptance.
* autfilt learned two options --generalized-rabin and
--generalized-streett to convert the acceptance conditions.
* genltl learned three new families: --dac-patterns=1..45,
--eh-patterns=1..12, and --sb-patterns=1..27. Unlike other options
these do not output scalable patterns, but simply a list of formulas
appearing in these three papers: Dwyer et al (FMSP'98), Etessami &
Holzmann (Concur'00), Somenzi & Bloem (CAV'00).
* genltl learned two options, --positive and --negative, to control
wether formulas should be output after negation or not (or both).
* The formater used by --format (for ltlfilt, ltlgrind, genltl,
randltl) or --stats (for autfilt, dstar2tgba, ltl2tgba, ltldo,
randaut) learned to recognize double-quoted fields and double the
double-quotes output inbetween as expected from RFC4180-compliant
CSV files. For instance
ltl2tgba -f 'a U "b+c"' --stats='"%f",%s'
will output
"a U ""b+c""",2
* The --csv-escape option of genltl, ltlfilt, ltlgrind, and randltl
is now deprecated. The option is still here, but hidden and
undocumented.
* The --stats option of autfilt, dstar2tgba, ltl2tgba, ltldo,
randaut learned to display the output (or input if that makes
sense) automaton as a HOA one-liner using %h (or %H), helping to
create CSV files contained automata.
* autfilt and dstar2tgba learned to read automata from columns in
CSV files, specified using the same filename/COLUMN syntax used by
tools reading formulas.
* Arguments passed to -x (in ltl2tgba, ltl2tgta, autfilt, dstar2tgba)
that are not used are now reported as they might be typos.
This ocurred a couple of times in our test-suite. A similar
check is done for the arguments of autfilt --sat-minimize=...
Library:
* The print_hoa() function will now output version 1.1 of the HOA
format when passed the "1.1" option (i.e., use -H1.1 from any
command-line tool). As far as Spot is concerned, this allows
negated properties to be expressed. Version 1 of the HOA format
is still the default, but we plan to default to version 1.1 in the
future.
* The "highlight-states" and "highlight-edges" named properties,
which were introduced in 1.99.8, will now be output using
"spot.highlight.edges:" and "spot.highlight.states:" headers if
version 1.1 of the HOA format is selected. The automaton parser
was secretly able of reading that since 1.99.8, but that is now
documented at https://spot.lrde.epita.fr/hoa.html#extensions
* highlight_nondet_states() and highlight_nondet_edges() are
new functions that define the above two named properties.
* is_deterministic(), is_terminal(), is_weak(), and
is_inherently_weak(), count_nondet_states(),
highlight_nondet_edges(), highlight_nondet_states() will update
the corresponding properties of the automaton as a side-effect of
their check.
* the sbacc() function, used by "ltl2tgba -S" and "autfilt -S" to
convert automata to state-based acceptance, learned some tricks
(using SCCs, pulling accepting marks common to all outgoing edges,
and pushing acceptance marks common to all incoming edges) to
reduce the number of additional states needed.
* to_generalized_rabin() and to_generalized_streett() are two new
functions that convert the acceptance condition as requested
without changing the transition structure.
* language_containment_checker now has default values for all
parameters of its constructor.
* spot::twa_run has a new method, project(), that can be used to
project a run found in a product onto one of the original operand.
This is for instance used by autfilt --highlight-word.
The old spot::project_twa_run() function has been removed: it was
not used anywhere in Spot, and had an obvious bug in its
implementation, so it cannot be missed by anyone.
* spot::twa has two new methods that supplement is_empty():
twa::accepting_run() and twa::accepting_word(). They compute
what their names suggest. Note that twa::accepting_run(), unlike
the two others, is currently restricted to automata with Fin-less
acceptance.
* spot::check_stutter_invariance() can now work on non-deterministic
automata for which no corresponding formula is known. This
implies that "autfilt --check=stutter" will now label all
automata, not just deterministic automata.
* New LTL and PSL simplification rules:
- if e is pure eventuality and g => e, then e U g = Fg
- if u is purely universal and u => g, then u R g = Gg
- {s[*0..j]}[]->b = {s[*1..j]}[]->b
- {s[*0..j]}<>->b = {s[*1..j]}<>->b
* spot::twa::succ_iterable renamed to
spot::internal::twa_succ_iterable to make it clear this is not for
public consumption.
* spot::fair_kripke::state_acceptance_conditions() renamed to
spot::fair_kripke::state_acceptance_mark() for consistency. This
is backward incompatible, but we are not aware of any actual use
of this method.
Python:
* The __format__() method for formula supports the same
operator-rewritting feature introduced in ltldo and ltlcross.
So "{:[i]s}".format(f) is the same as
"{:s}".format(f.unabbreviate("i")).
* Bindings for language_containment_checker were added.
* Bindings for randomize() were added.
* Iterating over edges via "aut.out(s)" or "aut.edges()"
now allows modifying the edge fields.
* Under IPython the spot.ltsmin module now offers a
%%pml magic to define promela models, compile them
with spins, and dynamically load them. This is
akin to the %%dve magic that was already supported.
* The %%dve and %%pml magics honor the SPOT_TMPDIR and
TMPDIR environment variables. This especially helps
when the current directory is read-only.
Documentation:
* A new example page shows how to test the equivalence of
two LTL/PSL formulas. https://spot.lrde.epita.fr/tut04.html
* A new page discusses explicit vs. on-the-fly interfaces for
exploring automata in C++. https://spot.lrde.epita.fr/tut50.html
* Another new page shows how to implement an on-the-fly Kripke
structure for a custom state space.
https://spot.lrde.epita.fr/tut51.html
* The concepts.html page now lists all named properties
used by automata.
Bug fixes:
* When ltlcross found a bug using a product of complemented
automata, the error message would report "Comp(Ni)*Comp(Pj)" as
non-empty while the actual culprit was "Comp(Nj)*Comp(Pi)".
* Fix some non-deterministic execution of minimize_wdba(), causing
test-suite failures with the future G++ 7, and clang 3.9.
* print_lbtt() had a memory leak when printing states without
successors.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.0.3
This is a maintenance release fixing minor issues found since the
releace of 2.0.2 last month. The most important changes are detailed
below.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.0.3.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
New in spot 2.0.3 (2016-07-11)
Bug fixes:
* The degen-lcache=1 option of the degeneralization algorithm (which
is a default option) did not behave exactly as documented: instead
of reusing the first level ever created for a state where the
choice of the level is free, it reused the last level ever used.
This caused some posterior simulation-based reductions to be less
efficient at reducing automata (on the average).
* The generalized testing automata displayed by the online
translator were incorrect (those output by ltl2tgta were OK).
* ltl2tgta should not offer options --ba, --monitor, --tgba and such.
* the relabel() function could incorrectly unregister old atomic
propositions even when they were still used in the output (e.g.,
if a&p0 is relabeled to p0&p1). This could cause ltldo and the
online translator to report errors.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.0.2.
This is a maintenance release fixing minor issues found since the
release of 2.0.1 last month. The most important changes are detailed
below.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.0.2.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
New in spot 2.0.2 (2016-06-17)
Documentation:
* We now have a citing page at https://spot.lrde.epita.fr/citing.html
providing a list of references about Spot.
* The Python examples have been augmented with the two examples
from our ATVA'16 tool paper.
Bug fixes:
* Fix compilation error observed with Clang++ 3.7.1 and GCC 6.1.1
headers.
* Fix an infinite recursion in relabel_bse().
* Various small typos and cosmetic cleanups.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.0.1.
This is a maintenance release fixing minor bugs, typos, and omissions.
The most important changes are detailed below.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.0.1.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
New in spot 2.0.1 (2016-05-09)
Library:
* twa::unregister_ap() and twa_graph::remove_unused_ap() are new
methods introduced to fix some of the bugs listed below.
Documentation:
* Add missing documentation for the option string passed to
spot::make_emptiness_check_instantiator().
* There is now a spot(7) man page listing all installed
command-line tools.
Python:
* The tgba_determinize() function is now accessible in Python.
Bug fixes:
* The automaton parser would choke on comments like /******/.
* check_strength() should also set negated properties.
* Fix autfilt to apply --simplify-exclusive-ap only after
the simplifications of (--small/--deterministic) have
been performed.
* The automaton parser did not fully register atomic propositions
for automata read from never claim or as LBTT.
* spot::ltsmin::kripke() had the same issue.
* The sub_stats_reachable() function used to count the number
of transitions based on the number of atomic propositions
actually *used* by the automaton instead of using the number
of AP declared.
* print_hoa() will now output all the atomic propositions that have
been registered, not only those that are used in the automaton.
(Note that it will also throw an exception if the automaton uses
an unregistered AP; this is how some of the above bugs were
found.)
* For Small or Deterministic preference, the postprocessor
will now unregister atomic propositions that are no longer
used in labels. Simplification of exclusive properties
and remove_ap::strip() will do similarly.
* bench/ltl2tgba/ was not working since the source code
reorganization of 1.99.7.
* Various typos and minor documentation fixes.
--
Alexandre Duret-Lutz
We are happy to announce the release of Spot 2.0!
Spot is a C++ library for model checking and manipulation
of temporal logic formula and omega-automata. It also
comes with command-line tools and Python bindings.
You can find the new release here:
http://www.lrde.epita.fr/dload/spot/spot-2.0.tar.gz
See https://spot.lrde.epita.fr/ for documentation and installation
instructions.
Spot 2.0 is the result of 28 months of work, as we starting working on
this branch after the release of Spot 1.2.1 (Dec 2013). It includes
contributions from Alexandre Lewkowicz, Amaury Fauchille, Étienne
Renault, Laurent Xu, Thibaud Michaud, and myself.
For people upgrading from Spot 1.2.6 (or older), the main news are as
follows:
* Automata now support acceptance conditions expressed as arbitrary
formulas over "marks" that must be seen infinitely often or
finitely often.
* The C++ API has been seriously overhauled and now requires a C++11
compiler. Backward compatibility has been broken in many ways:
see https://spot.lrde.epita.fr/upgrade2.html for help about
migrating old code. But now that the dust has settled, you should
not expect further API breakage in upcoming 2.x releases.
* The shell commands now include tools for processing automata. See
https://spot.lrde.epita.fr/tools.html for a list of all the tools,
and check https://spot.lrde.epita.fr/autfilt.html in particular.
The default interchange format is the Hanoi Omega
Automata format (HOA), but other formats are supported as well.
* The Python bindings are more complete, and even allow prototyping
low-level algorithms (for instance the page
https://spot.lrde.epita.fr/ipynb/product.html shows how to
implement a product of two automata with arbitrary acceptance).
Python bindings also interface nicely with IPython/Jupyter
notebooks. See https://spot.lrde.epita.fr/tut.html for short
examples of various tasks implemented in shell, C++, and Python.
For those upgrading from 1.99.9, the difference with Spot 2.0 is
rather thin. The following changes were included in Spot 2.0
(2016-04-11):
Command-line tools:
* ltlfilt now also support the --accept-word=WORD and
--reject-word=WORD options that were introduced in autfilt in the
previous version.
Python:
* The output of spot.atomic_prop_collect() is printable and
can now be passed directly to spot.ltsmin.model.kripke().
Library:
* digraph::valid_trans() renamed to digraph::is_valid_edge().
Documentation:
* The concepts page (https://spot.lrde.epita.fr/concepts.html) now
includes a highlevel description of the architecture, and some
notes aboute automata properties.
* More Doxygen documentation for spot::formula and spot::digraph.
See https://gitlab.lrde.epita.fr/spot/spot/blob/spot-2-0/NEWS for the
complete history of NEWS entries across previous releases.
Please direct any feedback to <spot(a)lrde.epita.fr>.
--
Alexandre Duret-Lutz
