I tried building the tcllibc library for Windows:

Windows 10
Latest MinGW release using GCC 8.1.0 installed today
Tcllib release 1.20 downloaded today
Windows critcl.exe downloaded from AK's site today

The following was echoed to the terminal screen:


sak.tcl critcl
------------------------------------------------------------------------
Building critcl components.
Note: you can ignore warnings for tcllibc.tcl, base64c.tcl and crcc.tcl.
------------------------------------------------------------------------
-cache -force -libdir ./modules -pkg tcllibc
Config:   win32-ix86-gcc
Build:    win32-ix86-gcc
Target:   win32-ix86
Source:   tcllibc.tcl  (provide tcllibc 0.3.15)md4c.tcl  (provide md4c 1.1.0)graph_c.tcl  (provide struct_graphc 2.4.3) (require Tcl 8.2)base32_c.tcl  (provide  ) (require Tcl 8.4)sets_c.tcl  (provide struct_setc 2.1.1) (require Tcl 8.4)jsonc.tcl  (provide jsonc 1.1.2) (require Tcl 8.4)pt_rdengine_c.tcl  (provide pt::rde::critcl 1.3.4) (require Tcl 8.4)pt_parse_peg_c.tcl  (provide pt_parse_peg_c 1.0.1) (require Tcl 8.4)uuid.tcl  (provide uuid 1.0.7) (require Tcl 8.5md5 2)tree_c.tcl  (provide struct_treec 2.1.1) (require Tcl 8.2)base32hex_c.tcl  (provide  ) (require Tcl 8.4)base64c.tcl  (provide base64c 0.1.0)uuencode.tcl  (provide uuencode 1.1.5) (require Tcl 8.2)yencode.tcl  (provide crc32 1.3.2) (require Tcl 8.2) (provide yencode 1.1.3) (require Tcl 8.2)sha1c.tcl  (provide sha1c 2.0.3)md5c.tcl  (provide md5c 0.12)crcc.tcl  (provide  )sum.tcl  (provide sum 1.1.2) (require Tcl 8.2)crc32.tcl (FAILED) md5cryptc.tcl  (provide md5cryptc 1.0)queue_c.tcl  (provide struct_queuec 1.3.1) (require Tcl 8.4)rc4c.tcl  (provide rc4c 1.1.0)sha256c.tcl  (provide sha256c 1.0.2)stack_c.tcl  (provide struct_stackc 1.3.1) (require Tcl 8.4)ipMoreC.tcl  (provide ipMorec 1.0)Compilation forced
Files left in
FAILURES 1
FAILED:
FAILED
FAILED   Tue Dec 24 15:16:05 CST 2019 -
FAILED
FAILED   gcc
FAILED          -c
FAILED          -fPIC
FAILED          -DUSE_THREAD_ALLOC=1
FAILED          -D_REENTRANT=1
FAILED          -D_THREAD_SAFE=1
FAILED          -DHAVE_PTHREAD_ATTR_SETSTACKSIZE=1
FAILED          -DHAVE_READDIR_R=1
FAILED          -DTCL_THREADS=1
FAILED          -DUSE_TCL_STUBS
FAILED
FAILED
FAILED          -o
FAILED
FAILED
FAILED          -O2
FAILED          -DNDEBUG
FAILED
FAILED   crc32.tcl:252:12: error: redefinition of 'tcl__crc_Crc32_c'
FAILED   note: previous definition of 'tcl__crc_Crc32_c' was here
FAILED    static int tcl__crc_Crc32_c(ClientData dummy, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
FAILED               ^~~~~~~~~~~~~~~~
FAILED   ERROR while compiling code in
FAILED   child process exited abnormally
FAILED