bug#24862: guile 2.0.13 build error under macOS 10.12 Sierra

[Matt Wette]

Using the same process as above I get the following on guile-2.0.12:

mwette$ time build-env guild compile --target="x86_64-apple-darwin16.1.0" -Wunbound-variable -Warity-mismatch -Wformat  -L "/Users/mwette/proj/scheme/guile/guile-2.0.13/module" -L /Users/mwette/proj/scheme/guile/guile-2.0.13/module/  -L /Users/mwette/proj/scheme/guile/guile-2.0.13/guile-readline/  -o "ice-9/eval.go" "ice-9/eval.scm" 

wrote `ice-9/eval.go'

real 0m0.484s

user 0m0.357s

sys 0m0.051s

Also, the “env DYLD… echo $DYLD…” demo above is clearly broken.  But I have verified that DYLD_LIBRARY_PATH is filters out of env copy in the shell.