Windows, envvars: envvar names may contain characters that are illegal on Linux

[laszlocsomor]

Description of the problem / feature request / question:

Environment variable names may contain "(", "{", "*", "/", and who knows what else.

If they do, bootstrapping breaks in scripts/bootstrap/compile.sh when it invokes the freshly bootstrapped Bazel.

The Bazel client also happily passes such envvars to the server, which may choke on them too.

If possible, provide a minimal example to reproduce the problem:

C:\>set Foo({*/=Bar
C:\>c:\tools\msys64\msys2.exe

$ env | grep Foo
Foo({*/=Bar

$ cd /c/work/bazel-0.5.0-dist

$ ./compile.sh
(...)
🍃  Building Bazel with Bazel.
.scripts/bootstrap/compile.sh: eval: line 332: syntax error near unexpected token `('
scripts/bootstrap/compile.sh: eval: line 332: `value=$ProgramFiles(x86)'
scripts/bootstrap/compile.sh: eval: line 332: syntax error near unexpected token `('
scripts/bootstrap/compile.sh: eval: line 332: `value=$CommonProgramFiles(x86)'

Environment info

• Operating System: Windows 10

• Bazel version (output of bazel info release): 0.5.0

[laszlocsomor]

Correction: this won't break bootstrapping if I just unset these envvars in cmd.exe, then run msys from there (so it won't inherit these envvars in the first place).

[laszlocsomor]

More correction: no, bootstrapping breaks further down the road. :(