I just tried to build Qt-5.7.1 using AlienBob's scripts and that is a no to too. Worked fine before the last updates to current. Will have to look in detail at what changed. Lots of requirements seem to now be missing -
./check_package.sh -l build.txt
++ Checking logfile 'build.txt' (no news is good news):
225: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
238: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
246: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
365: dlopen.cpp
.text.startup+0x9): undefined reference to `dlopen'
366: collect2: error: ld returned 1 exit status
367: gmake: *** [Makefile:87: dlopen] Error 1
375: db2.cpp:40:20: fatal error: sqlcli.h: No such file or directory
377: gmake: *** [Makefile:183: db2.o] Error 1
381: ibase.cpp:40:19: fatal error: ibase.h: No such file or directory
383: gmake: *** [Makefile:183: ibase.o] Error 1
391: oci.cpp:40:17: fatal error: oci.h: No such file or directory
393: gmake: *** [Makefile:183: oci.o] Error 1
398: /usr/lib64/gcc/x86_64-slackware-linux/5.4.0/../../../../x86_64-slackware-linux/bin/ld: cannot find -lodbc
399: collect2: error: ld returned 1 exit status
400: gmake: *** [Makefile:87: odbc] Error 1
408: psql.cpp:40:22: fatal error: libpq-fe.h: No such file or directory
410: gmake: *** [Makefile:183: psql.o] Error 1
418: sqlite2.cpp:40:20: fatal error: sqlite.h: No such file or directory
420: gmake: *** [Makefile:183: sqlite2.o] Error 1
424: tds.cpp:40:22: fatal error: sybfront.h: No such file or directory
426: gmake: *** [Makefile:183: tds.o] Error 1
506: tslib.cpp:40:19: fatal error: tslib.h: No such file or directory
508: gmake: *** [Makefile:183: tslib.o] Error 1
611: Project ERROR: mirclient development package not found
627: eglfs-brcm.cpp:42:22: fatal error: bcm_host.h: No such file or directory
629: gmake: *** [Makefile:183: eglfs-brcm.o] Error 1
650: eglfs-mali.cpp:40:30: fatal error: EGL/fbdev_window.h: No such file or directory
652: gmake: *** [Makefile:183: eglfs-mali.o] Error 1
657: eglfs-mali-2.cpp:47:5: error: ‘mali_native_window’ was not declared in this scope
660: eglfs-mali-2.cpp:47:25: error: ‘w’ was not declared in this scope
663: gmake: *** [Makefile:183: eglfs-mali-2.o] Error 1
667: eglfs-viv.cpp:41:28: fatal error: EGL/eglvivante.h: No such file or directory
669: gmake: *** [Makefile:183: eglfs-viv.o] Error 1
673: doubleconversion.cpp:40:49: fatal error: double-conversion/double-conversion.h: No such file or directory
675: gmake: *** [Makefile:183: doubleconversion.o] Error 1
758: ppoll.cpp:55:34: error: ‘nullptr’ was not declared in this scope
761: gmake: *** [Makefile:183: ppoll.o] Error 1
769: pollts.cpp:56:12: error: ‘:
ollts’ has not been declared
772: pollts.cpp:56:35: error: ‘nullptr’ was not declared in this scope
775: gmake: *** [Makefile:183: pollts.o] Error 1
791: openvg.cpp:46:23: fatal error: VG/openvg.h: No such file or directory
793: gmake: *** [Makefile:183: openvg.o] Error 1
797: openvg.cpp:46:23: fatal error: VG/openvg.h: No such file or directory
799: gmake: *** [Makefile:183: openvg.o] Error 1
803: openvg.cpp:44:23: fatal error: vg/openvg.h: No such file or directory
805: gmake: *** [Makefile:183: openvg.o] Error 1
809: openvg.cpp:44:23: fatal error: vg/openvg.h: No such file or directory
811: gmake: *** [Makefile:183: openvg.o] Error 1
1059: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
1072: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
1080: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
1277: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
1290: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
1298: lastError = QT_READDIR_R(dir, mt_file.data(), &dirEntry);
12042: System jsoncpp not found. Using Chromium's copy.
12043: System protobuf not found. Using Chromium's copy.
12044: Compatible system libvpx not found.
More after this. Will keep digging.