[ProGet] Unexpected redirect when accessing Maven package with non-standard version starting with a character

[koksime.yap_5909]

Hi ProGet team,

I’ve encountered an issue when uploading Maven packages to ProGet that use non-standard version strings starting with a character.

Example:

• Package name: package-alpha-0.1.pom
• Version: alpha-0.1

When I upload this package and then try to access the .pom file directly from the feed, instead of downloading the file as usual, the browser is redirected to a page ending with / (e.g., .../package-alpha-0.1/), rather than returning the file contents.

However, this behavior does not occur when the non-standard version starts with a number.
For example:

• 0.1_a-l-p-h-a works correctly — the .pom file is downloaded normally.

Steps to Reproduce:

1. Upload a Maven package with a non-standard version starting with a letter (e.g. alpha-0.1).
2. Attempt to access the .pom file directly from the feed URL.
3. Observe that the request is redirected to a URL ending in / instead of downloading the file.

Expected Behavior:
Accessing the .pom file should return the file contents directly, similar to when using a numeric-starting version.

Actual Behavior:
Accessing the .pom file with a version starting with a character causes a redirect, preventing the file from being downloaded.

Questions:

• Is this the expected behavior in ProGet for non-standard Maven versions?
• If not, how can I configure ProGet or the Maven feed so that files with such versions are handled correctly (i.e., downloaded instead of redirected)?

Environment:

• ProGet version: 25.0.12; container
• Feed type: Maven
• Client: Browser / curl

Thanks for your help!

[atripp]

Hi @koksime-yap_5909 ,

I'm afraid this is a known limitation with Maven feeds; we made the assumption that package authors would follow the bare-minimum of Maven versioning: packages start with letters, versions start with numbers.

The only examples we found that were counter to that were 20+ year old artifacts, however, we've since learned that authors still mistakenly use these incorrect versions.

Unfortunately, supporting these types of versions require a complex/risky change.

Maven is a file-based API and the client just GETs/PUTs files. However, ProGet is not a file server so we need to actually parse the URLs to figure out which artifact/package the files refer to. In this case, we parse package-alpha-0.1 as package-alpha (version 0.1), not package (version alpha-0.1). Hence, why it's not working.

~~If these are your internal packages, the easiest solution is to follow the standard:
https://docs.oracle.com/middleware/1212/core/MAVEN/maven_version.htm~~

Thanks,
Alana

[atripp]

Hi @koksime-yap_5909 ,

Just as a quick update! Given that this is a more wide-spread problem, we've fixed the code and plan to release in ProGet 2026 (or possibly sooner, if we can make it low-risk enough in a mainteannce release).

Thanks,
Alana

[koksime.yap_5909]

Hi @atripp,

That’s great news - really glad to hear the fix is on the way! I’m excited to test it out once it’s available. Please do let me know when the update is released.

Thanks so much for the help!

[atripp]

Hi @koksime-yap_5909,

Good news, it's available now for testing! We're considering merging to ProGet 2025, or maybe keeping for ProGet 2026?

Anyway, I posted a lot more detail now:
https://forums.inedo.com/topic/5696/proget-is-unable-to-download-maven-packages-that-use-a-nonstandard-versioning-scheme/2

Thanks,
Alana

FYI -- locked this, in case anyone has comments/questions on that change, I guess that post will be the "official" thread at this point :)