]>
granicus.if.org Git - graphviz/log
Matthew Fernandez [Sat, 13 Feb 2021 20:47:16 +0000 (20:47 +0000)]
Merge branch 'smattr/
1FE7F116 -BD57-44DB-A463-
C712472A1CA6 ' into 'master'
add details of updating the website to the release procedure
See merge request graphviz/graphviz!1729
Matthew Fernandez [Wed, 3 Feb 2021 01:48:11 +0000 (17:48 -0800)]
add details of updating the website to the release procedure
This is addressing the following point I made in the 2.46.0 retrospective:
We probably need to incorporate www2.graphviz.org and graphviz.gitlab.io
actions into the release steps in DEVELOPERS.md.
It would be nice to further automate some of this in future.
Matthew Fernandez [Sat, 13 Feb 2021 20:13:28 +0000 (20:13 +0000)]
Merge branch 'smattr/
7654BD6A -00FB-419C-9CEE-
58F314E9471A ' into 'master'
fix HTML validation issues in FAQ.html
See merge request graphviz/graphviz!1727
Matthew Fernandez [Tue, 2 Feb 2021 05:21:26 +0000 (21:21 -0800)]
fix HTML validation issues in FAQ.html
Related to #1861.
Matthew Fernandez [Sat, 13 Feb 2021 19:36:38 +0000 (19:36 +0000)]
Merge branch 'smattr/
E0AA0C62 -2E41-45C8-8F0E-
C7CF13B57772 ' into 'master'
remove Python 2 pytest installation in CI
Closes #1886
See merge request graphviz/graphviz!1726
Matthew Fernandez [Tue, 2 Feb 2021 05:02:58 +0000 (21:02 -0800)]
remove Python 2 pytest installation in CI
We only support running the test suite with Python 3. Closes #1886.
Matthew Fernandez [Sat, 13 Feb 2021 19:02:31 +0000 (19:02 +0000)]
Merge branch 'smattr/
eb990658 -b367-436d-84a5-
fcb9dec533c3 ' into 'master'
remove dead suffix parsing code
Closes #1933
See merge request graphviz/graphviz!1725
Matthew Fernandez [Mon, 1 Feb 2021 03:32:56 +0000 (19:32 -0800)]
delete no longer used strton
Matthew Fernandez [Mon, 1 Feb 2021 03:11:37 +0000 (19:11 -0800)]
remove dead code for suffix handling of parsed numbers
This code attempted to handle a numeric suffix indicating a multiplier (e.g. 'k'
for 1024). However, the preceding logic that constructs a temporary buffer for
it to parse from does not anticipate suffixes and copy them to the buffer. The
(inactive) suffix code is considered only useful for describing file sizes, so
not relevant to enable for Graphviz. Closes #1933.
Matthew Fernandez [Sat, 13 Feb 2021 18:29:22 +0000 (18:29 +0000)]
Merge branch 'smattr/
D1537418 -F027-4305-8650-
1E45D1B2F6B1 ' into 'master'
update Graphviz URLs in comments
See merge request graphviz/graphviz!1724
Matthew Fernandez [Sun, 31 Jan 2021 19:39:37 +0000 (11:39 -0800)]
update Graphviz URLs in comments
Matthew Fernandez [Sat, 13 Feb 2021 17:54:33 +0000 (09:54 -0800)]
Merge 'Start 2.46.2 development series' into master
Matthew Fernandez [Sat, 13 Feb 2021 17:03:53 +0000 (09:03 -0800)]
Start 2.46.2 development series
Matthew Fernandez [Sat, 13 Feb 2021 17:02:13 +0000 (17:02 +0000)]
Merge branch 'smattr/
63291F41 -E610-4E9F-B12E-
1566969C0FDA ' into 'master'
Stable Release 2.46.1
See merge request graphviz/graphviz!1732
Matthew Fernandez [Sat, 6 Feb 2021 19:34:28 +0000 (11:34 -0800)]
Stable Release 2.46.1
Matthew Fernandez [Sat, 6 Feb 2021 19:23:11 +0000 (19:23 +0000)]
Merge branch 'smattr/
DD8B4ECD -399B-4BEF-AD77-
3EF40BA4402E ' into 'master'
Properly fill graphviz_version.h (!1706 plus test case)
See merge request graphviz/graphviz!1723
Kevin Funk [Thu, 21 Jan 2021 10:39:01 +0000 (11:39 +0100)]
Properly fill graphviz_version.h
Make sure the variables used inside the header template are populated.
Prior to this patch we ended up with this in the generated
graphviz_version.h:
#define PACKAGE_VERSION ""
Edit by Matthew Fernandez: Added changelog entry and flipped polarity on the
CMake test case for this.
Matthew Fernandez [Sun, 31 Jan 2021 17:48:06 +0000 (09:48 -0800)]
add a test of PACKAGE_VERSION
Related to !1706.
Matthew Fernandez [Sat, 6 Feb 2021 18:49:51 +0000 (18:49 +0000)]
Merge branch 'smattr/
D39EA669 -23A2-4D0E-A8BD-
7FC55FC1C35E ' into 'master'
apply some C99 to vmalloc
See merge request graphviz/graphviz!1722
Matthew Fernandez [Sun, 31 Jan 2021 01:25:22 +0000 (17:25 -0800)]
#pragma once instead of old-style header guards in vmalloc
These are supported by all recent compilers.
Matthew Fernandez [Sun, 31 Jan 2021 01:24:42 +0000 (17:24 -0800)]
remove Vim modeline markers from vmalloc
These have no effect for non-Vim users or Vim users with modeline disabled.
clang-format is a better modern solution to this problem.
Matthew Fernandez [Sun, 31 Jan 2021 01:21:55 +0000 (17:21 -0800)]
take advantage of some C99 features in vmalloc
Matthew Fernandez [Sun, 31 Jan 2021 02:24:51 +0000 (18:24 -0800)]
compile vmalloc tests with C99
This should have been included in
fe3f9411d2c59b463ab1b64eecfd19f2db55d2fc .
Matthew Fernandez [Sat, 6 Feb 2021 05:26:49 +0000 (05:26 +0000)]
Merge branch 'smattr/
B7B7989C -A893-415A-B27A-
B365C1D44997 ' into 'master'
drop support for Fedora 31
See merge request graphviz/graphviz!1721
Matthew Fernandez [Sun, 31 Jan 2021 01:00:22 +0000 (17:00 -0800)]
drop support for Fedora 31
Fedora 31 was EOLed in November 2020 [0].
[0]: https://lists.fedoraproject.org/archives/list/announce@lists.fedoraproject.org/thread/NU5AENRUFG4XK5D34SJN5FZPLYMZF6ZQ/
Matthew Fernandez [Sun, 31 Jan 2021 00:56:30 +0000 (16:56 -0800)]
move Fedora CMake testing to Fedora 32
Fedora 31 was EOLed in November 2020 [0].
[0]: https://lists.fedoraproject.org/archives/list/announce@lists.fedoraproject.org/thread/NU5AENRUFG4XK5D34SJN5FZPLYMZF6ZQ/
Matthew Fernandez [Sat, 6 Feb 2021 04:32:54 +0000 (04:32 +0000)]
Merge branch 'smattr/
77EC4CE8 -9933-43C1-B3BB-
B9F65F3901ED ' into 'master'
remove alternate vsnprintf code
See merge request graphviz/graphviz!1720
Matthew Fernandez [Sat, 30 Jan 2021 22:00:01 +0000 (14:00 -0800)]
remove some unnecessary casts
Matthew Fernandez [Sat, 30 Jan 2021 21:58:34 +0000 (13:58 -0800)]
remove vsnprintf detection
We no longer depend on this and simply assume vsnprintf is available.
Matthew Fernandez [Sat, 30 Jan 2021 21:51:49 +0000 (13:51 -0800)]
remove alternate vsnprintf paths
As of
fe3f9411d2c59b463ab1b64eecfd19f2db55d2fc , we build with C99 where
vsnprintf is require. Hence we no longer need other code paths.
Matthew Fernandez [Sat, 6 Feb 2021 03:12:28 +0000 (03:12 +0000)]
Merge branch 'smattr/
F614351E -E612-4E14-A869-
F958C2FDF07E ' into 'master'
use release version for generic package version when possible
See merge request graphviz/graphviz!1719
Matthew Fernandez [Sat, 30 Jan 2021 21:05:11 +0000 (13:05 -0800)]
use release version for generic package version when possible
This addresses my comment from the 2.46.0 retrospective:
I realized after the fact that, though the generic package versions have a
restricted format, our release versions fit that format. I.e. we could have
the generated 0.0.287364… versions for commit snapshots, but for packages that
contain a release we could use a version that is the same as the release
version itself, e.g. 2.46.0.
Now generic packages that correspond to a stable release will get the same
generic package version as the release version itself. This should avoid some
user confusion in future.
Matthew Fernandez [Sat, 30 Jan 2021 21:02:11 +0000 (13:02 -0800)]
reorder version computation steps in deployment
Matthew Fernandez [Sat, 30 Jan 2021 21:00:59 +0000 (13:00 -0800)]
abbreviate some use of enumerate()
Matthew Fernandez [Sat, 6 Feb 2021 01:48:15 +0000 (01:48 +0000)]
Merge branch 'smattr/
DA75A76F -4160-460E-8F0E-
E2159B71E1C2 ' into 'master'
migrate test suite to Python 3.6+
Closes #1870
See merge request graphviz/graphviz!1718
Matthew Fernandez [Sat, 2 Jan 2021 03:23:51 +0000 (19:23 -0800)]
use f-strings in Python test scripts
Now that we have Python 3.6 as a base line requirement, we can use f-strings
pervasively. Related to #1870.
Matthew Fernandez [Sat, 2 Jan 2021 04:01:10 +0000 (20:01 -0800)]
use Pathlib for path-typed variables in the test suite
As of Python 3.4, this is the Pythonic way of dealing with file system paths.
Matthew Fernandez [Sat, 2 Jan 2021 03:20:21 +0000 (19:20 -0800)]
set a new base line of Python 3.6 for running the test suite
Closes #1870.
Matthew Fernandez [Fri, 5 Feb 2021 04:41:46 +0000 (04:41 +0000)]
Merge branch 'smattr/
19153a68 -1b2c-4716-962d-
c07b057af4ed ' into 'master'
fix: no longer lose \n within quoted strings
Closes #1931
See merge request graphviz/graphviz!1717
Matthew Fernandez [Sat, 30 Jan 2021 03:01:34 +0000 (19:01 -0800)]
fix: no longer lose \n within quoted strings
9bdd24cae96d01fc6b2a940bc87d27edeb5d84a7 addressed a problem where line number
tracking was not working across new line characters embedded within quoted
strings. However it accidentally unmasked another bug involving a parsing rule
that swallowed new lines which was incorrectly enabled within quoted strings.
Fixes #1931.
Matthew Fernandez [Sat, 30 Jan 2021 02:16:35 +0000 (18:16 -0800)]
test case for #1931
Matthew Fernandez [Wed, 3 Feb 2021 01:32:50 +0000 (01:32 +0000)]
Merge branch 'smattr/
56867813 -653e-4fc1-822a-
4d4f56154de5 ' into 'master'
fix: add header guard to graphviz_version.h
Closes #1929
See merge request graphviz/graphviz!1716
Matthew Fernandez [Wed, 27 Jan 2021 02:25:09 +0000 (18:25 -0800)]
fix: add header guard to graphviz_version.h
To prevent users #including this multiple times getting compiler warnings.
Closes #1929.
Matthew Fernandez [Sun, 31 Jan 2021 03:46:32 +0000 (03:46 +0000)]
Merge branch 'smattr/
850CBB25 -AAEA-471D-BB06-
0C826F1276EF ' into 'master'
some rtest.py tweaks and generate a .tar.xz portable source
Closes #454
See merge request graphviz/graphviz!1715
Matthew Fernandez [Mon, 25 Jan 2021 00:48:38 +0000 (16:48 -0800)]
also build a .tar.xz archive for distribution
Closes #454.
Matthew Fernandez [Mon, 25 Jan 2021 00:24:28 +0000 (16:24 -0800)]
fix: teach rtest.py how to find its default files regardless of CWD
If rtest.py is run from a different directory -- e.g. from a top-level make
check-recursive -- it could not find its default inputs.
Matthew Fernandez [Mon, 25 Jan 2021 00:06:51 +0000 (16:06 -0800)]
fix: make tools findable by rtest.py in a `make check-recursive`
Matthew Fernandez [Sun, 24 Jan 2021 23:57:15 +0000 (15:57 -0800)]
fix path to rtest.py when triggered by `make check-recursive`
Matthew Fernandez [Sun, 31 Jan 2021 01:01:49 +0000 (17:01 -0800)]
Merge !1714 into master
Alex Henrie [Mon, 25 Jan 2021 00:39:37 +0000 (17:39 -0700)]
Remove dead assignments from SparseMatrix_import_matrix_market
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from extoken_fn
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from makeDotGraph
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from GFXinit
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from scan_num
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignments from mincross_step
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from SparseMatrix_coordinate_form_add_entries
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from constrained_majorization_new
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignments from self(Bottom|Top|Right|Left)
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from parseSegs
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from mincross
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from edge_distinct_coloring
Alex Henrie [Mon, 25 Jan 2021 00:29:35 +0000 (17:29 -0700)]
Remove dead assignment from map_path
Matthew Fernandez [Sat, 30 Jan 2021 23:01:57 +0000 (23:01 +0000)]
Merge branch 'smattr/
28CF1899 -48F1-437D-B47E-
F356FBF1EF2B ' into 'master'
remove legacy CVS references
See merge request graphviz/graphviz!1712
Matthew Fernandez [Sun, 24 Jan 2021 21:57:55 +0000 (13:57 -0800)]
remove legacy CVS references
Now that Graphviz lives in Git, these references are no longer relevant. Closes
#1798.
Matthew Fernandez [Sat, 30 Jan 2021 22:17:06 +0000 (22:17 +0000)]
Merge branch 'smattr/
B831E666 -D040-4688-8954-
B4CA975B36FB ' into 'master'
fix some unchecked allocations in gxl2gv
Closes #1928
See merge request graphviz/graphviz!1710
Matthew Fernandez [Sun, 24 Jan 2021 18:02:53 +0000 (10:02 -0800)]
fix: use gcalloc wrapper for some allocations that cannot tolerate failure
It would have been nicer to just call the existing gcalloc() in libcommon, but
this is not exported in the MS Build compilation flow and altering this has some
unclear side effects. Related to #1928.
Matthew Fernandez [Sun, 24 Jan 2021 17:53:57 +0000 (09:53 -0800)]
fix: exit on allocation failure in genUserdata
Closes #1928.
Matthew Fernandez [Sun, 24 Jan 2021 17:52:40 +0000 (09:52 -0800)]
fix unchecked allocation failure when making an item in gxl2gv
The callers of this callback in libcdt can tolerate this function returning
NULL. Related to #1928.
Matthew Fernandez [Sat, 30 Jan 2021 21:43:34 +0000 (13:43 -0800)]
Merge !1711 into HEAD
Alex Henrie [Sun, 24 Jan 2021 20:17:41 +0000 (13:17 -0700)]
Fix potential null pointer dereferences in UniformStressSmoother_new
Matthew Fernandez [Sat, 30 Jan 2021 20:16:32 +0000 (20:16 +0000)]
Merge branch 'smattr/
18710D9F -BA89-489A-BE10-
CBD90E44A0EF ' into 'master'
fix typo in pathscross()
Closes #1926
See merge request graphviz/graphviz!1708
Matthew Fernandez [Sun, 24 Jan 2021 02:24:53 +0000 (18:24 -0800)]
remove unnecessary bracketing in pathscross()
Matthew Fernandez [Sun, 24 Jan 2021 02:21:01 +0000 (18:21 -0800)]
fix typo in comparison in pathscross()
This was identified by GCC -Wlogical-op:
dotsplines.c: In function ‘pathscross’:
dotsplines.c:2498:32: warning: logical ‘and’ of equal expressions [-Wlogical-op]
if ((ND_out(n0).size != 1) && (ND_out(n0).size != 1))
^~
Changes in this commit are the fix suggested by Stephen. Fixes #1926.
Matthew Fernandez [Sun, 24 Jan 2021 02:18:18 +0000 (18:18 -0800)]
remove some use of K&R function syntax
This was deprecated in favor of ANSI syntax some time ago.
Matthew Fernandez [Sat, 30 Jan 2021 19:43:03 +0000 (11:43 -0800)]
Merge branch !1709 into HEAD
Matthew Fernandez [Sat, 30 Jan 2021 19:15:07 +0000 (11:15 -0800)]
changelog entry for prior commit
Alex Henrie [Sun, 24 Jan 2021 20:14:16 +0000 (13:14 -0700)]
Fix bad free in lefty
Matthew Fernandez [Sat, 30 Jan 2021 18:47:35 +0000 (18:47 +0000)]
Merge branch 'smattr/
3b850695 -fd6d-437a-b88f-
2d65888d30b9 ' into 'master'
move to C99 and C++11
Closes #1832, #1833, and #1924
See merge request graphviz/graphviz!1707
Matthew Fernandez [Sat, 23 Jan 2021 23:05:07 +0000 (15:05 -0800)]
fix overflow check in sparse
Switching to C99 compilation exposes the following compiler warning:
general.c:364:21: warning: logical ‘or’ of collectively exhaustive tests is always true [-Wlogical-op]
if (val > INT_MAX || val < INT_MIN) return 0;
^~
This change fixes the comparison to do what seems to have been intended. Related
to #1833.
Matthew Fernandez [Sat, 23 Jan 2021 22:49:52 +0000 (14:49 -0800)]
remove cached allocation in userout
We can avoid using a static pointer and avoid the allocation loop in this
function by simply leveraging the C99 semantics of vsnprintf. The result is more
readable code. Closes #1924.
Matthew Fernandez [Sat, 2 Jan 2021 18:33:43 +0000 (10:33 -0800)]
use C99 standard for compiling C code
Closes #1833.
Matthew Fernandez [Sat, 2 Jan 2021 21:55:57 +0000 (13:55 -0800)]
remove C++11 check when compiling with Qt5
The build now requires C++11 at the top level, so any Qt5 code can assume C++11
is available and the relevant compiler flag(s) have already been appended.
Related to #1832.
Matthew Fernandez [Sat, 2 Jan 2021 21:54:38 +0000 (13:54 -0800)]
require C++11 support for compiling
Closes #1832.
Matthew Fernandez [Sat, 2 Jan 2021 21:46:14 +0000 (13:46 -0800)]
fix: stop ignoring changes to m4/*
These files are version controlled but were being manually unignored. Thus
changes to any missing entries (e.g. ax_check_compile_flag.m4) went unnoticed.
Now we don't ignore anything in this subdirectory because no generated files are
expected to end up there.
Matthew Fernandez [Sun, 24 Jan 2021 18:02:18 +0000 (18:02 +0000)]
Merge branch 'smattr/
BE94C9C3 -A6E3-4C5F-B6D8-
FA00B0FDD413 ' into 'master'
add some details about downstream projects
See merge request graphviz/graphviz!1705
Matthew Fernandez [Thu, 21 Jan 2021 01:02:02 +0000 (17:02 -0800)]
add some details about downstream projects
Matthew Fernandez [Sun, 24 Jan 2021 02:17:42 +0000 (02:17 +0000)]
Merge branch 'smattr/
E64BA158 -2E02-488E-9F5A-
2ADC94C357C6 ' into 'master'
fix: suppress re-running CI on tagged commits
Closes #1901
See merge request graphviz/graphviz!1703
Matthew Fernandez [Sun, 17 Jan 2021 02:33:33 +0000 (18:33 -0800)]
fix: suppress re-running CI on tagged commits
Several tasks in the CI setup were allowed to run on tagged commits. This meant
that pushing a new tag would result in re-running CI on the tagged commit. This
was already confusing, but was compounded by these unrestricted tasks depending
on non-tag-only tasks. The result was that CI would stall and fail because
dependencies could not be satisfied.
To fix this we simply disallow all CI on a tag. This means that a tagged commit
that is not on any branch will not be tested. However, no one should be pushing
such a commit to the Graphviz repository. All tagged commits that are on a
branch will be tested via their SHA. This is not expected to cause any problems
as the Graphviz build system never checks the Git tag or whether a commit is
tagged at all.
Fixes #1901.
Matthew Fernandez [Sun, 24 Jan 2021 01:13:20 +0000 (01:13 +0000)]
Merge branch 'smattr/
480984E2 -F863-4F4B-8813-
9EFB371B8CCC ' into 'master'
document how to build Graphviz for developers
See merge request graphviz/graphviz!1700
Matthew Fernandez [Thu, 7 Jan 2021 03:36:12 +0000 (19:36 -0800)]
document how to build Graphviz for developers
Matthew Fernandez [Sun, 24 Jan 2021 00:38:48 +0000 (16:38 -0800)]
Merge !1699
Matthew Fernandez [Sat, 23 Jan 2021 23:51:45 +0000 (15:51 -0800)]
add changelog item about prior commits
Alex Henrie [Sat, 9 Jan 2021 09:02:07 +0000 (02:02 -0700)]
Fix memory leak in make_map_internal
Alex Henrie [Thu, 7 Jan 2021 03:35:57 +0000 (20:35 -0700)]
Fix memory leak in gv_get_ps_fontlist
Alex Henrie [Thu, 7 Jan 2021 03:35:57 +0000 (20:35 -0700)]
Fix memory leaks in Multilevel_(MQ|Modularity)_Clustering_establish
Matthew Fernandez [Sat, 23 Jan 2021 23:46:53 +0000 (23:46 +0000)]
Merge branch 'smattr/
529f1002 -e2fa-4706-ba00-
2b3ad0811c15 ' into 'master'
unify and correct RectArea implementations
Closes #1906
See merge request graphviz/graphviz!1697
Matthew Fernandez [Sat, 12 Dec 2020 16:45:19 +0000 (08:45 -0800)]
fix: unify and correct RectArea implementations
Two implementations of RectArea were provided that implemented the overflow
check based on whether there was a larger type than unsigned int available. It
is unnecessary to maintain multiple implementations of this as the overflow
check can be written in a width-independent way.
Moreover the `LLONG_MAX > UINT_MAX` alternative was incorrect. E.g. on x86-64
where this alternative is used, if `r->boundary[i + NUMDIMS] - r->boundary[i]`
is `UINT_MAX` and the accumulated value in `a_test` is `(long long)UINT_MAX`,
the multiplication (which is done on operands promoted to long long) overflows
causing undefined behavior. In practice, you would likely get a negative value,
that then erroneously passes the overflow check.
Related to #1898. Fixes #1906.
Matthew Fernandez [Mon, 28 Dec 2020 03:13:58 +0000 (19:13 -0800)]
fix: remove Circo test of root.gv from rtest.py-tested graphs
This graph generates an overflow when computing the area of rectangles required
to layout it out. It should be rejected but it currently incorrectly is not.
Related to #1906.
Matthew Fernandez [Sat, 23 Jan 2021 23:14:25 +0000 (23:14 +0000)]
Merge branch 'smattr/
AB3ED35D -6FC9-4811-92FB-
9C0FB6F5E9E4 ' into 'master'
Autotools build system support for Guile 2.2
See merge request graphviz/graphviz!1696
Matthew Fernandez [Sun, 27 Dec 2020 22:19:27 +0000 (14:19 -0800)]
support Guile 2.2 in the Autotools build system
The build system detection of Guile was relying on a binary named guile-config.
As of Guile 2.2, coexisting versions of Guile are supported and so the
guile-config binary is suffixed with its version. The result of this mismatch
was that the build system would fail to detect Guile 2.2 on platforms that did
not provide a guile-config redirection shim.
Guile 3.0 has already been out for awhile, but this commit does not add support
for it. The devel packages for it do not seem yet available on any major Linux
distro. We should extend this support to 3.0 when it becomes more widely
available if Graphviz' use of Guile is compatible. Related to #1885.