don't let environment settings perturb build Setting the envvars, LIB_CLOCK_GETTIME, LIB_EACCESS or LIB_NANOSLEEP could cause a configure-time and/or build-time malfunction. Typically, a configure-time function-in-library test is performed via code like this: LIB_VAR= AC_SUBST([LIB_VAR]) prefix_saved_LIBS=$LIBS AC_SEARCH_LIBS([FUNC], [LIB_NAME], [test "$ac_cv_search_FUNC" = "none required" || LIB_VAR=$ac_cv_search_FUNC]) LIBS=$prefix_saved_LIBS However, in each of the files affected by this change, the LIB_VAR= initialization was omitted. Thus, when set in the environment, its value would propagate into generated Makefiles when FUNC is not found in LIB_NAME. * m4/clock_time.m4 (gl_CLOCK_TIME): Initialize AC_SUBST'd var. * m4/euidaccess.m4 (gl_PREREQ_EUIDACCESS): Likewise. * m4/nanosleep.m4 (gl_FUNC_NANOSLEEP): Likewise.