The symbol 'yylex' comes from a flex generated file. Not sure how this isn't being seen in all builds... This will need to link with a flex generated file. In this case, all I can see is scan.c, which is generated from scan.l. So should ltp_bump link with scan.o? If not, then why would ltp-bump need to link with libfl.so?

Can you find the log for linking 'ltp-bump' in one of the successful builds?

14:59:13 make[1]: Entering directory `/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan'
14:59:13 /scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan/Makefile:43: ltp-scanner will not be built because a working copy of lex was not found
14:59:13 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc -g -O2 -g -O2 -fno-strict-aliasing -pipe -Wall -W -g -O2 -Wold-style-definition -D_FORTIFY_SOURCE=2 -Wno-error -I/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan -I../include -I../include  -c -o ltp-bump.o ltp-bump.c
14:59:13 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc -g -O2 -g -O2 -fno-strict-aliasing -pipe -Wall -W -g -O2 -Wold-style-definition -D_FORTIFY_SOURCE=2 -Wno-error -I/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan -I../include -I../include  -c -o zoolib.o zoolib.c
14:59:13 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc   -L../lib  ltp-bump.o zoolib.o   -lm  -o ltp-bump
14:59:13 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc -g -O2 -g -O2 -fno-strict-aliasing -pipe -Wall -W -g -O2 -Wold-style-definition -D_FORTIFY_SOURCE=2 -Wno-error -I/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan -I../include -I../include  -c -o ltp-pan.o ltp-pan.c
14:59:14 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc -g -O2 -g -O2 -fno-strict-aliasing -pipe -Wall -W -g -O2 -Wold-style-definition -D_FORTIFY_SOURCE=2 -Wno-error -I/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan -I../include -I../include  -c -o splitstr.o splitstr.c
14:59:14 /home/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/integration/toolchain/linaro-4.7/bin/arm-linux-gnueabihf-gcc   -L../lib  ltp-pan.o zoolib.o splitstr.o   -lm  -o ltp-pan
14:59:14 make[1]: Leaving directory `/scratch/lcpdbld/jenkins_ws/workspace/start-ltp-ddt-next-build/ltp-ddt/pan'