See https://groups.google.com/forum/#!topic/minisat/FCocZsC8oMQ
This seems to only be a problem with newer versions of g++, and
upstream development seems to have stopped in 2013.

diff -rupN minisat-2.2.0/core/SolverTypes.h minisat-2.2.0.patched/core/SolverTypes.h
--- a/minisat/core/SolverTypes.h	2010-07-10 17:07:36.000000000 +0100
+++ b/minisat/core/SolverTypes.h	2014-03-29 11:57:49.000000000 +0000
@@ -47,7 +47,7 @@ struct Lit {
     int     x;

     // Use this as a constructor:
-    friend Lit mkLit(Var var, bool sign = false);
+    //friend Lit mkLit(Var var, bool sign = false);

     bool operator == (Lit p) const { return x == p.x; }
     bool operator != (Lit p) const { return x != p.x; }
@@ -55,7 +55,7 @@ struct Lit {
 };


-inline  Lit  mkLit     (Var var, bool sign) { Lit p; p.x = var + var + (int)sign; return p; }
+inline  Lit  mkLit     (Var var, bool sign = false) { Lit p; p.x = var + var + (int)sign; return p; }
 inline  Lit  operator ~(Lit p)              { Lit q; q.x = p.x ^ 1; return q; }
 inline  Lit  operator ^(Lit p, bool b)      { Lit q; q.x = p.x ^ (unsigned int)b; return q; }
 inline  bool sign      (Lit p)              { return p.x & 1; }
uix/tree/scripts?id=bbdb686878c8fe0d7983b19e348847acd552ed9e'>tree</a><a href='/guix/commit/scripts?id=bbdb686878c8fe0d7983b19e348847acd552ed9e'>commit</a><a href='/guix/diff/scripts?id=bbdb686878c8fe0d7983b19e348847acd552ed9e'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/scripts'>
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<option value='grep'>log msg</option>
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<div class='path'>path: <a href='/guix/log/?id=bbdb686878c8fe0d7983b19e348847acd552ed9e'>root</a>/<a href='/guix/log/scripts?id=bbdb686878c8fe0d7983b19e348847acd552ed9e'>scripts</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/scripts?id=bbdb686878c8fe0d7983b19e348847acd552ed9e&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-12-11 19:06:53 +0100'>2020-12-11</span></td><td><a href='/guix/commit/scripts?id=fd247542215fbd10f28980f3d5255014b150e95a'>build: 'script/guix' uses our own 'guile' executable.</a><span class='msg-avail'>...<span class='msg-tooltip'>* Makefile.am (do_subst): Substitute @abs_top_builddir@.
* scripts/guix.in: Use it.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-09 12:02:27 +0200'>2018-06-09</span></td><td><a href='/guix/commit/scripts?id=75e24d7b0e19ab2164aecb340e82d07d2b9714e7'>pull: Install the new Guix in a profile.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/pull.scm (%pull-version): New variable.
(build-from-source): Pass #:pull-version to BUILD.
(whole-package-for-legacy, derivation-&gt;manifest-entry): New procedure.
(build-and-install): Rewrite in terms of 'build-and-use-profile'.
* guix/scripts/system.scm (maybe-suggest-running-guix-pull)[latest]:
Switch to "/current".
* scripts/guix.in (augment-load-paths!): Remove use of
~/.config/guix/latest.
* build-aux/compile-as-derivation.scm: Replace "/guix/latest/" with
"/current/share/guile/site/X.Y"
* guix/scripts.scm (warn-about-old-distro)[age]: Check "/current"
instead of "/latest".
* doc/guix.texi (Invoking guix pull): Document it.
* doc/contributing.texi (Running Guix Before It Is Installed): Remove
footnote about abusing ~/.config/guix/latest.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-01-28 23:14:55 +0100'>2018-01-28</span></td><td><a href='/guix/commit/scripts?id=63666a348af5ef5190cbe9611c40f2b9188b7967'>guix: Let Emacs detect “scripts/guix.in” appropriate mode.</a><span class='msg-avail'>...<span class='msg-tooltip'>Since commit 6f774d481839f87178c5895ac2d661e141f879b8 which introduces the use
of Guile's meta switch in “scripts/guix.in”, Emacs was not using ‘scheme-mode’
for this file.

* scripts/guix.in: Replace "-*- scheme -*-" with a local variable.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Mathieu Lirzin</td></tr>
<tr><td><span title='2018-01-23 15:01:15 +0100'>2018-01-23</span></td><td><a href='/guix/commit/scripts?id=6f774d481839f87178c5895ac2d661e141f879b8'>guix: Refactor script.</a><span class='msg-avail'>...<span class='msg-tooltip'>* scripts/guix.in: Remove empty surrounding ‘let’.  Define 'main' as the
procedure called when running the script.
(maybe-augment-load-paths!): Rename to ...
(augment-load-paths!): ... this.  Use 'and=&gt;' for 'file-exists?'.
(run-guix-main): Rename to ...
(main): ... this.  Call 'augment-load-paths!'.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Mathieu Lirzin</td></tr>
<tr><td><span title='2018-01-23 10:13:16 +0100'>2018-01-23</span></td><td><a href='/guix/commit/scripts?id=cba386c1295b7054df22dfb4662b1b92f668e2c0'>build: Expand ‘scripts/guix’ at Make time.</a><span class='msg-avail'>...<span class='msg-tooltip'>This moves the complexity of Autotools variable expansion outside of the
application code.

* scripts/guix.in (config-lookup): Delete.
(maybe-augment-load-paths!, run-guix-main): Use fully expanded variables
instead of calling ‘config-lookup’.
* configure.ac: Don't use AC_CONFIG_FILES for ‘scripts/guix’.
Use AC_PROG_SED.
* Makefile.am (scripts/guix): New rule.
(do_subst): New variable.
(CLEANFILES, EXTRA_DIST): Adapt.

Co-authored-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Mathieu Lirzin</td></tr>