I am quite not sure the version of RFA that you are using.

I also couldn't find libTibMsg.a in RFA C++ 7.6.2.L1 Linux package.

In the package, there are libTibMsg.so for the TibMsg shared library and libRFA.a for the RFA static library. For static build, I think that the TibMsg library is in libRFA.a.

Following is the MakeFile used to build the legacy application.

ifeq ($(USE_STATIC),1)
	RFA_LIBS = $(LIB_DIR)/Static/libRFA.a
	EXE_DIR=$(OUTPUT_DIR)/Static
	LN_HOMEPATH=../..
else
	RFA_LIBS = -lRFA_Common -lRFA_Config -lRFA_Logger -lRFA_SessionLayer -lRFA_Adapter -lRFA_Connections -lRFA_Connections_MD -lAnsiPage -lDacs -lwndacs -lTibMsg
	EXE_DIR=$(OUTPUT_DIR)
	LN_HOMEPATH=..
endif

From the MakeFile, you will see that it uses libRFA.a for static build and uses -lTibMsg for linking to the TibMsg shared library.