Unit tests fail in non Linux environments

[na4zagin3]

Automation tests in https://github.com/ocaml/opam-repository/pull/17295 failed due to the following reasons:

Travis#28797.1: Failed to mask temp dirs

- -Setting up SATySFi env at @@with_env@@ 
- +Setting up SATySFi env at /var/folders/17/5mc7816d3mndxjqgplq6057w0000gn/T/Satyrographosabecf9with_env

Travis#28797.2 & Travis#28797.4: Collation order for files

- (cd _build/default && /usr/bin/git diff --no-index --color=always -u test/testcases/command_install__emptyDist.expected test/testcases/command_install__emptyDist.output)
- diff --git a/test/testcases/command_install__emptyDist.expected b/test/testcases/command_install__emptyDist.output
- index f4553c8..9746ef6 100644
- --- a/test/testcases/command_install__emptyDist.expected
- +++ b/test/testcases/command_install__emptyDist.output
- @@ -12,8 +12,8 @@ Installation completed!
-  ------------------------------------------------------------
-  @@dest_dir@@
-  @@dest_dir@@/dest
- -@@dest_dir@@/dest/metadata
-  @@dest_dir@@/dest/.satyrographos
- +@@dest_dir@@/dest/metadata
-  ------------------------------------------------------------