I've had a quick look and textosaurus appears to need a patch, which I found in the void-packages repository:
--- src/libtextosaurus/saurus/miscellaneous/textapplication.h 2018-11-27 07:50:39.000000000 +0100
+++ src/libtextosaurus/saurus/miscellaneous/textapplication.h 2020-07-27 12:33:06.612447044 +0200
@@ -8,6 +8,7 @@
#include "definitions/definitions.h"
#include "saurus/miscellaneous/textapplicationsettings.h"
+#include <QDropEvent>
#include <QIcon>
class TextEditor;
With this patch applied, libtextosaurus compiles correctly, but the linking fails. The Makefile produces the following command:
g++ -shared -lexecinfo -L/usr/pkg/lib -L/usr/lib -Wl,-R/usr/lib -Wl,-R/usr/pkg/lib -L/usr/X11R7/lib -Wl,-R/usr/X11R7/lib -Wl,-O1 -pthread -Wl,-rpath,/usr/pkg/qt5/lib -shared -Wl,-soname,libtextosaurus.so -o dynamicshortcuts.o [...snip...] moc_ScintillaEditBase.o moc_ScintillaQt.o -L/usr/pkg/lib -L/usr/X11R7/lib /usr/pkg/qt5/lib/libQt5PrintSupport.so /usr/pkg/qt5/lib/libQt5Svg.so /usr/pkg/qt5/lib/libQt5Widgets.so /usr/pkg/qt5/lib/libQt5Gui.so /usr/pkg/qt5/lib/libQt5Network.so /usr/pkg/qt5/lib/libQt5Core.so -lGL
As you can see, the name of the output file is missing after the -o option, so a 9 MB a.out file is produced instead of libtextosaurus.so. If I fix this manually and continue with a "make install", make tells me "Nothing to be done for 'install'." 😠
The commands I executed to get there are:
git clone https://github.com/martinrotter/textosaurus.git
cd textosaurus/src
/usr/pkg/qt5/bin/qmake -r "CONFIG+=release" "PREFIX=/usr/pkg" ../build.pro
make
(I also - unsuccessfully - tried from the textosaurus and textosaurus/src/libtextosaurus directories, with build.pro and libtextosaurus.pro respectively instead of ../build.pro)
My guess is that qmake needs more options when building on NetBSD, likely variable assignments, though I have no idea which... :/