Shadow can fail trying to reference deps.edn git dependencies on MS-Windows

[ikappaki]

Hi,

I've encountered an issue with shadow failing on MS-Windows when the project root directory and a library downloaded via deps.edn wiht git are in different drives (e.g. D: and C: respectively):

d:\clj\issues\issue-shadow-cljs-rel-path>powershell -command clojure -M:shadow watch browser
Downloading: thheller/shadow-cljs/2.16.6/shadow-cljs-2.16.6.pom from clojars
Downloading: thheller/shadow-cljs/2.16.6/shadow-cljs-2.16.6.jar from clojars
[2021-12-04 16:17:14.341 - WARNING] TCP Port 9630 in use.
[2021-12-04 16:17:14.355 - WARNING] TCP Port 9631 in use.
failed to start service
{:id :classpath}
ExceptionInfo: failed to start service
        shadow.runtime.services/start-many/fn--9691 (services.clj:135)
...
        clojure.main.main (main.java:40)
Caused by:
IllegalArgumentException: 'other' has different root
        sun.nio.fs.WindowsPath.relativize (WindowsPath.java:404)
        sun.nio.fs.WindowsPath.relativize (WindowsPath.java:42)
        shadow.build.classpath/project-rel-path (classpath.clj:719)
        shadow.build.classpath/project-rel-path (classpath.clj:718)
        shadow.build.classpath/find-fs-resources* (classpath.clj:767)
        shadow.build.classpath/find-fs-resources* (classpath.clj:764)
        shadow.build.classpath/find-fs-resources (classpath.clj:792)
        shadow.build.classpath/find-fs-resources (classpath.clj:791)
        shadow.build.classpath/find-resources (classpath.clj:801)
        shadow.build.classpath/find-resources (classpath.clj:795)
        shadow.build.classpath/index-path* (classpath.clj:1034)
        shadow.build.classpath/index-path* (classpath.clj:1031)
 ...
        shadow.build.classpath/index-classpath/fn--11375/fn--11376 (classpath.clj:1167)
...
        shadow.build.classpath/index-classpath/fn--11375 (classpath.clj:1167)
        shadow.build.classpath/index-classpath (classpath.clj:1166)
        shadow.build.classpath/index-classpath (classpath.clj:1161)
        shadow.build.classpath/index-classpath (classpath.clj:1163)
        shadow.build.classpath/index-classpath (classpath.clj:1161)
        shadow.cljs.devtools.server.common/fn--16790 (common.clj:95)
        shadow.cljs.devtools.server.common/fn--16790 (common.clj:93)
...

This is because it cannot find a relative path between the Project and the downloaded git library.

To reproduce on MS-Windows, create the below project on a different drive (say somewhere on drive D:) than clojure cli stores the github dependencies (normally stored on drive C: under C:\Users\<username>\.gitlibs):

e.g. under D:\clj\issues\issue-shadow-cljs-rel-path\

1. shadow-cljs.edn

{:deps {:aliases [:shadow]}
 :builds {:browser {:target :browser
                    :output-to "public/js/viewer.js"
                    :output-dir "public/js"
                    }}}

2. deps.edn

{:paths ["src"]
 :deps {re-frame/re-frame {:git/url "https://github.com/nextjournal/freerange"
                           :git/sha "8cf68c30722a4c6f8f948a134c900d7a656ecad4"}
        }
 
 :aliases
 {:shadow {:extra-deps {thheller/shadow-cljs {:mvn/version "2.16.6"}}
           :main-opts ["-m" "shadow.cljs.devtools.cli"]}
  }}

3. invoke shadow

d:\clj\issues\issue-shadow-cljs-rel-path> powershell -command clojure -M:shadow watch browser

The above error is returned.

The cause of the issue is that shadow is trying to find a relative path from the project to the dep with shadow.build.classpath/project-rel-path, but it cannot and throws the above example. There is no relative path because there is no common root between D:\clj\issues\issue-shadow-cljs-rel-path and C:\Users\ikappaki\.gitlibs\libs\re-frame\re-frame\8cf68c30722a4c6f8f948a134c900d7a656ecad4\src (one starts with D: the other with C:).

If we relocate the project on the C drive, then the above succeeds, since there is a relative path between the two C:\clj\issues\issue-shadow-cljs-rel-path and C:\Users\ikappaki\.gitlibs\libs\re-frame\re-frame\8cf68c30722a4c6f8f948a134c900d7a656ecad4\src, namely ..\..\..\Users\ikappaki\.gitlibs\libs\re-frame\re-frame\8cf68c30722a4c6f8f948a134c900d7a656ecad4\src. The same works on *nix, because there is always a common root / amongst any absolute paths, thus a relative path with ../... can always be created.

It is not obvious to me what the correct solution is, have shadow.build.classpath/project-rel-path return nil? Though the callers appear to always make use of the return value.

Thanks!

[thheller]

Should be fixed as of 2.16.7.

[ikappaki]

Should be fixed as of 2.16.7.

Thanks! tested to work as expected.