This post on page 6.

After many years of lurking, I may finally have something worthy of contribution.

I successfully compiled QT3 and the latest showeq on a Pi 3B+ running the Raspbian Stretch 2018-10-09 desktop image:

-- Install the following packages: subversion libtool automake libpcap-dev libx11-dev libxext-dev gcc-4.9 g++-4.9
-- Download qt-x11-free-3.3.8b.tar.gz from https://download.qt.io/archive/qt/3/
-- Set some environment variables in .bashrc or whatever location is appropriate for your shell. Adjust paths for your system, if desired.
Code:
QTDIR=/usr/local/qt3
PATH=$QTDIR/bin:$PATH
MANPATH=$QTDIR/doc/man:$MANPATH
LD_LIBRARY_PATH=$QTDIR/lib:$LD_LIBRARY_PATH

export QTDIR PATH MANPATH LD_LIBRARY_PATH
-- Save the following code to a file, and apply the patch to the qt sources, via 'patch -p1 < patchfile' :
Code:
--- qt-x11-free-3.3.8b/src/tools/qglobal.h.orig 2007-04-24 09:02:36.000000000 -0400
+++ qt-x11-free-3.3.8b/src/tools/qglobal.h 2007-04-24 09:03:02.000000000 -0400
@@ -315,9 +315,9 @@
QString bloat. However, gcc 3.4 doesn't allow us to create references to
members of a packed struct. (Pointers are OK, because then you
supposedly know what you are doing.) */
-# if (defined(__arm__) || defined(__ARMEL__)) && !defined(QT_MOC_CPP)
+# if (defined(__arm__) || defined(__ARMEL__)) && !defined(QT_MOC_CPP) && !defined(__ARM_EABI__)
# define Q_PACKED __attribute__ ((packed))
-# if __GNUC__ == 3 && __GNUC_MINOR__ >= 4
+# if __GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
# define Q_NO_PACKED_REFERENCE
# endif
# endif
--- qt-x11-free-3.3.8b/src/tools/qstring.h.orig 2007-04-24 09:03:11.000000000 -0400
+++ qt-x11-free-3.3.8b/src/tools/qstring.h 2007-04-24 09:03:27.000000000 -0400
@@ -194,7 +194,7 @@
char latin1() const { return ucs > 0xff ? 0 : (char) ucs; }
ushort unicode() const { return ucs; }
#ifdef Q_NO_PACKED_REFERENCE
- ushort &unicode() { return *(&ucs); }
+ ushort &unicode() { return *((ushort *)&ucs); }
#else
ushort &unicode() { return ucs; }
#endif
--- qt-x11-free-3.3.8b/src/tools/qvaluelist.h 2008-01-15 13:09:13.000000000 -0600
+++ qt-x11-free-3.3.8b/src/tools/qvaluelist.h 2018-10-29 22:35:36.253629483 -0500
@@ -51,6 +51,7 @@
#include <iterator>
#include <list>
#endif
+#include <stddef.h>

//#define QT_CHECK_VALUELIST_RANGE

--- qt-x11-free-3.3.8b/src/tools/qmap.h 2008-01-15 13:09:13.000000000 -0600
+++ qt-x11-free-3.3.8b/src/tools/qmap.h 2018-10-29 22:36:05.563527018 -0500
@@ -53,6 +53,7 @@
#include <iterator>
#include <map>
#endif
+#include <stddef.h>

//#define QT_CHECK_MAP_RANGE
-- configure qt3, enabling threading and setting a prefix:
Code:
./configure -thread -prefix /usr/local/qt-3.3.8b
-- make -j4 (take a small nap while this builds)
-- as root, execute 'make install'
-- i create a symlink, to match my QTDIR environment variable
Code:
ln -s /usr/local/qt-3.3.8b /usr/local/qt3
-- checkout seq
-- make -f Makefile.dist build
-- configure, using gcc-4.9 instead of gcc-6.3 (Newby suggested this here)
Code:
CXX=g++-4.9 CC=gcc-4.9 ./configure
-- make and make install as usual

After getting this built, I have one remaining issue that isn't relevant to my usage, so I'm posting this with the hope that it gets someone closer to a general solution.

When running directly on the Pi desktop, showeq isn't finding a default Helvetica font, so the menu texts are all placeholder boxes instead of letters. I like to run my Pi headless, exporting the DISPLAY to a remote X server on a windows client machine. The menu fonts look normal to me there, so I've no need to pursue this issue any further, but I suspect that it's possible to modify seqdef.xml or showeq.xml to override Helvetica with one of the fonts included on the Pi desktop image.

You do have to make a change for the bazaar search as noted on the top of this page