hitting one of the dark corners of the env. that suddenly is in public use :(

the scrip itself is no magic, consisting of just 

s/\(\.\.\\\)\{2,4\}/..\\/g

which obviously won't work with cygwin. it also assumes that linking is alway
done one level below the module root...

so hacking a cygwin version (two backslashes to slash):

s/\(\.\.\/\)\{2,4\}/..\//g

placing it in solenv/bin and changing its usage ([_]tg_app.mk and [_]tg_shl.mk) from

$(COMMON_ENV_TOOLS)$/chrel.sed

to

$(SOLARENV)$/bin$/chrel.sed

could be a hacky workaround...

Created attachment 52351 [details]
Patch for solenv

I put your suggestions into a patch, see before, and it indeed makes ucbhelper
build.

Thanks. Masterfix?

this "fix" wasn't meant to be committed as it is quite likely to break the 4nt
build here. also i'd like PRJ variable to appear in the sed script.
any suggestions how to modify chrel.sed welcome

for now, having both sed (native and cygwin - shouldn't affect each other) lines
in chrel.sed seems to be they way to go to get this fix in fast. no smart
detection of the directory level but being able to link again...
i'll a bit of building with that and propose it as a masterfix if noone objects.

*** Issue 87675 has been marked as a duplicate of this issue. ***

proposed fix done as masterfix for m6

.