A no-changes build of sqsh sent to the PPA builders fails with the following message:
gcc -L/lib cmd_alias.o cmd_bcp.o cmd_buf.o cmd_connect.o cmd_do.o cmd_echo.o cmd_exit.o cmd_for.o cmd_func.o cmd_go.o cmd_help.o cmd_history.o cmd_if.o cmd_input.o cmd_jobs.o cmd_kill.o cmd_lock.o cmd_loop.o cmd_misc.o cmd_read.o cmd_reconnect.o cmd_redraw.o cmd_reset.o cmd_return.o cmd_rpc.o cmd_set.o cmd_shell.o cmd_show.o cmd_sleep.o cmd_wait.o cmd_warranty.o cmd_while.o var_ctlib.o var_date.o var_debug.o var_dsp.o var_hist.o var_misc.o var_passwd.o var_readline.o var_thresh.o dsp.o dsp_bcp.o dsp_csv.o dsp_conv.o dsp_desc.o dsp_horiz.o dsp_html.o dsp_meta.o dsp_none.o dsp_out.o dsp_pretty.o dsp_vert.o dsp_x.o sqsh_alias.o sqsh_args.o sqsh_avl.o sqsh_buf.o sqsh_cmd.o sqsh_compat.o sqsh_ctx.o sqsh_debug.o sqsh_env.o sqsh_error.o sqsh_expand.o sqsh_fd.o sqsh_filter.o sqsh_fork.o sqsh_func.o sqsh_getopt.o sqsh_global.o sqsh_history.o sqsh_init.o sqsh_job.o sqsh_readline.o sqsh_sig.o sqsh_sigcld.o sqsh_stdin.o sqsh_strchr.o sqsh_tok.o sqsh_varbuf.o sqsh_main.o -lct -lXm -lreadline -o sqsh
/usr/bin/ld: dsp_x.o: undefined reference to symbol 'XtAddCallback'
/usr/bin/ld: note: 'XtAddCallback' is defined in DSO /usr/lib/i386-linux-gnu/libXt.so.6 so try adding it to the linker command line
/usr/lib/i386-linux-gnu/libXt.so.6: could not read symbols: Invalid operation
The attached patch fixes the FTBFS by explicitly linking libXt.