Package check result: WARNING

Check: whether package can be installed, Result: WARNING
  Found the following significant warnings:
    i0tk00.f:5:20: warning: type of ‘cstak’ does not match original declaration [-Wlto-type-mismatch]
    istkqu.f:11:20: warning: type of ‘cstak’ does not match original declaration [-Wlto-type-mismatch]
    istkrl.f:13:20: warning: type of ‘cstak’ does not match original declaration [-Wlto-type-mismatch]
    stkdmp.f:16:20: warning: type of ‘cstak’ does not match original declaration [-Wlto-type-mismatch]
    u9dmp.f:39:20: warning: type of ‘cstak’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:23:13: warning: type of ‘setupdate_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:22:13: warning: type of ‘setup_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:21:13: warning: type of ‘setkfilsm_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:20:13: warning: type of ‘setfor_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:19:13: warning: type of ‘setcom_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:18:13: warning: type of ‘loop_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:14:13: warning: type of ‘cspec_’ does not match original declaration [-Wlto-type-mismatch]
    cts_init.c:13:13: warning: type of ‘complete_’ does not match original declaration [-Wlto-type-mismatch]
    a9rntd.f:41:21: warning: type of ‘dblepr’ does not match original declaration [-Wlto-type-mismatch]
    loop.f:91:22: warning: type of ‘dblepr’ does not match original declaration [-Wlto-type-mismatch]
  See ‘/home/hornik/tmp/CRAN_special_LTO/cts.Rcheck/00install.out’ for details.
  Used C compiler: ‘gcc-15 (Debian 15.2.0-16) 15.2.0’
  Used Fortran compiler: ‘GNU Fortran (Debian 15.2.0-16) 15.2.0’