Build error under Net+O/S for release version only

I have a NetOS installation which used to work fine.
Now building a project only works in debug mode; in release mode I get errors:
Compressing blram.bin to blram.bin.compressed
Using LZSS Encoder/Decode (v2)

Input bytes: 75328
Output bytes: 39658
Compression ratio: 48%

Generating header.bin from blram.bin.compressed for BOOT header
Image Type: Compressed
Image Size: 39658
Flash Offset: 0x0
RAM Address: 0x0
Backup Image Address: 0x0
/usr/bin/sh: /usr/bin/tclsh: No such file or directory
make[3]: *** [blram.o] Error 127
make[3]: Target all' not remade because of errors. make[2]: *** [bootloader/ramImage/blram.o] Error 2 make[2]: Target all’ not remade because of errors.
make[1]: *** [mylocalall] Error 2
make[1]: Target `all’ not remade because of errors.
make: *** [bsp/7_5/dd_generic_me9210/lib/libbsp.a] Error 2

This happens regardless of whether its an existing project or a newly created one.
Looks as if its related to creation of the bootloader

This started after I had a disc problem on the system with the NetOS code; nominally its all been recovered OK, and a comparison with another installation hasn’t thrown up any errors (checked both cygwin and NetOS directories). Nominally nothing has changed on the PC; just a new disc drive with full data.
Project workspace is on another (network) drive so didn’t directly suffer.

As far as I can tell, programs sh and tclsh shouldn’t be in the user/bin directory under cygwin.

Projects are all connect ME9210 and CC9P9215.

Has anyone else encountered this problem?

looks like your cygwin installation got corrupt:
/usr/bin/tclsh: No such file or directory
probably file C:\cygwin420\bin clsh.exe is missing or corrupt