Clojure Q&A - Recent activity in tools.build

Commented: Can 'write-pom' in tools.build support providing additional dependencies in the pom.xml with scope 'provided'?

Thu, 11 Dec 2025 11:33:40 +0000

maybe the scope option can be taken from the deps.edn file itself? it's just additional metadata used for uberjars, and deps.edn doesn't seem to complain when I add `:scope :provided` in a dependency's data map, so it doesn't seem to affect other cli functionality

Closed: How to ignore :src-pom default for clojure.tools.build.api/write-pom if ./pom.xml exists?

Tue, 28 Oct 2025 13:43:16 +0000

I have a project that generates more than one jar artifact. For project A, I have ./pom.xml that is used as a template and everything works fine.

For project B, I want to generate a pom.xml that's completely separate from project A which does not use ./pom.xml as a template. I generate the pom as follows:

(require '[clojure.tools.build.api :as b])
(b/write-pom {:class-dir class-dir
                  :pom-data pom-data
                  :lib coord
                  :version version
                  :basis basis})

However, since ./pom.xml exists, it is used as a template. Explicitly passing nil for :src-pom doesn't help. The only workaround I could find was to pass in a bogus path for :src-pom.

Answer selected: tools.build compile-clj capture out/err

Tue, 29 Jul 2025 17:34:13 +0000

Logged as https://clojure.atlassian.net/browse/TBUILD-46

Commented: tools.build fails with http_proxy/https_proxy set

Thu, 03 Jul 2025 13:41:28 +0000

Putting the proxy information into `settings.xml` worked. I tried different approaches by setting the proxy information in environment variables for Maven, but all those failed.

Commented: switch tools.build to pull from jars rather than exploding onto disk

Sat, 10 May 2025 03:52:14 +0000

I tried deleting the answer, but there doesn't seem to be a way to do that — but it is possible to convert it into a comment, which I did. Now I'm trying to delete the duplicate comment I created in the meantime… sorry about the mess.

Commented: Please consider making tools.build pom.properties reproducible (e.g. the "Generated by" date)

Sun, 16 Mar 2025 19:01:14 +0000

OK, I think the patch above will probably apply directly, but I'll double-check.

Commented: clojure.tools.build.api/process + ignore hangs when process has large output

Mon, 10 Mar 2025 19:22:39 +0000

In addition, if the output is very large, the following will hang:

(defn get-history [_]
  (b/git-process {:git-args ["log" "--after=2025-01-01" "--pretty=format:%D%n%B"]}))

roklenarcic on Slack says:

this code is wrong:
(let [proc (.start pb)
          exit (.waitFor proc)
          out-str (when (= out :capture) (copy-stream (.getInputStream proc)))
          err-str (when (= err :capture) (copy-stream (.getErrorStream proc)))]
      (cond-> {:exit exit}
        out-str (assoc :out out-str)
        err-str (assoc :err err-str)))

you cannot await for process exit before setting up something that will drain the streams
that will cause process to block if the output is big enough

Alex says:

this process stuff (which was the precursor of the new 1.12 clojure.java.process api) definitely needs some clean up in this area. I actually thought I had done that but must have confused it with the work there

Commented: Is it possible to build an uberwar using deps.edn using tools.build or other tool?

Sat, 08 Jun 2024 14:48:08 +0000

Did you get resolution on this? I'm working on migrating a java app using a spring framework that runs on tomcat over to clojure driven. Are you available for a call?

Commented: Warn about user.clj during build compilation

Wed, 28 Feb 2024 19:10:51 +0000

Yes, that was logged at https://ask.clojure.org/index.php/12854/jvm-property-to-turn-user-clj-loading-off

Answer selected: tools.build.api/uber uses EDN for data_readers.cljc -- it should support reader conditionals

Fri, 10 Mar 2023 04:08:44 +0000

Thought this had been fixed https://clojure.atlassian.net/plugins/servlet/mobile?originPath=/browse/TBUILD-32#issue/TBUILD-32

Closed: Files in deps :local/root :git/url will directly copy into uberjar without go through conflict-handlers

Fri, 13 Jan 2023 23:32:22 +0000

https://github.com/clojure/tools.build/blob/1309f935b098123eb807c972a053eeab77f6f4cd/src/main/clojure/clojure/tools/build/tasks/uber.clj#L172

The handling between jar and lib folders like git deps or local root are completely different. In my case, I have some config files in edn format (duct's duct_hierarchy.edn) exists in both jar deps and git deps. My additional conflict handler is never receiving the edn file that exists in git deps.

Is it the expected behaviour? I can imagine that even LICENSE or data_readers.clj would suffer the same issue. e.g. being overrided by files in git deps.

Commented: Will tools.build be released as a jar?

Wed, 14 Dec 2022 20:32:30 +0000

Looks like it has been done! Thanks all! https://search.maven.org/artifact/org.clojure/tools.build/0.8.4/jar

> Clojure already does not have reproducible builds in terms of compiled code

I think a specific version of Clojure applied to the same source code will always generate the same output. (Unless someone is introducing time/random seed in the compilation tasks?)

> I'm curious, what about Clojure builds is not reproducible from source?

Well, me too, honestly. But all said, if we have an immutable asset we can point to, we have reduced the set of things that can introduce nondeterminism.

Retagged: Ability to customise java-cmd in tools.build

Tue, 06 Sep 2022 14:47:45 +0000

Moving the original question from Clojurians Slack:

When moving one of my projects to JDK 19 I was pointing clojure to the jdk using the JAVA_CMD env var. Everything was fine til I hit the uber jar step in the CI, where it simply refused to recognise the jdk 19 functions.

Took me a while and including reading the tools.build source to realise why it wasn't propagating the JAVA_CMD var and turns out I had to read env and send the :java_cmd in the b/compile-clj call.

I can see why the behaviour is like this, but would :java_cmd defaulting to the value of JAVA_CMD something that could be considered? Feels a bit more intuitive for me, as mostly the invocations of tools.build fns would be from the shell.

Closed: Exception in EdnReader$DispatchReader

Tue, 28 Jun 2022 19:25:41 +0000

(from https://clojurians.slack.com/archives/C02B5GHQWP4/p1656165951371179)
When I include tick/tick {:mvn/version "0.5.0-RC6"} as a dep, I get the exception below. I cannot reproduce in an deps.edn that only contains this library so I believe there is some kind of conflict with another library.

{:clojure.main/message
"Execution error at clojure.tools.build.tasks.uber/conflict-data-readers (uber.clj:90).\nNo dispatch macro for: ?\n",
:clojure.main/triage
{:clojure.error/class java.lang.RuntimeException,
:clojure.error/line 90,
:clojure.error/cause "No dispatch macro for: ?",
:clojure.error/symbol
clojure.tools.build.tasks.uber/conflict-data-readers,
:clojure.error/source "uber.clj",
:clojure.error/phase :execution},
:clojure.main/trace
{:via
[{:type java.lang.RuntimeException,

:message "No dispatch macro for: ?",
:at [clojure.lang.Util runtimeException "Util.java" 221]}],

:trace
[[clojure.lang.Util runtimeException "Util.java" 221]
[clojure.lang.EdnReader$DispatchReader invoke "EdnReader.java" 552]
[clojure.lang.EdnReader readDelimitedList "EdnReader.java" 757]
[clojure.lang.EdnReader$MapReader invoke "EdnReader.java" 680]
[clojure.lang.EdnReader read "EdnReader.java" 145]
[clojure.lang.EdnReader read "EdnReader.java" 111]
[clojure.lang.EdnReader readString "EdnReader.java" 67]
[clojure.edn$read_string invokeStatic "edn.clj" 46]
[clojure.edn$read_string invokeStatic "edn.clj" 37]
[clojure.edn$read_string invoke "edn.clj" 37]
[clojure.tools.build.tasks.uber$conflict_data_readers

invokeStatic
"uber.clj"
90]

[clojure.tools.build.tasks.uber$conflict_data_readers

invoke
"uber.clj"
86]

[clojure.tools.build.tasks.uber$handle_conflict

invokeStatic
"uber.clj"
120]

[clojure.tools.build.tasks.uber$handle_conflict

invoke
"uber.clj"
111]

[clojure.tools.build.tasks.uber$explode invokeStatic "uber.clj" 157]
[clojure.tools.build.tasks.uber$explode invoke "uber.clj" 137]
[clojure.tools.build.tasks.uber$uber$fn3537$fn3541

invoke
"uber.clj"
253]

[clojure.lang.PersistentVector reduce "PersistentVector.java" 343]
[clojure.core$reduce invokeStatic "core.clj" 6885]
[clojure.core$reduce invoke "core.clj" 6868]
[clojure.tools.build.tasks.uber$uber$fn__3537 invoke "uber.clj" 252]
[clojure.core.protocols$iter_reduce invokeStatic "protocols.clj" 49]
[clojure.core.protocols$fn__8230 invokeStatic "protocols.clj" 75]
[clojure.core.protocols$fn__8230 invoke "protocols.clj" 75]
[clojure.core.protocols$fn8178$G8173__8191

invoke
"protocols.clj"
13]

[clojure.core$reduce invokeStatic "core.clj" 6886]
[clojure.core$reduce invoke "core.clj" 6868]
[clojure.tools.build.tasks.uber$uber invokeStatic "uber.clj" 250]
[clojure.tools.build.tasks.uber$uber invoke "uber.clj" 237]
[clojure.lang.Var invoke "Var.java" 384]
[clojure.tools.build.api$uber invokeStatic "api.clj" 480]
[clojure.tools.build.api$uber invoke "api.clj" 408]
[org.corfield.build$uber invokeStatic "build.clj" 250]
[org.corfield.build$uber invoke "build.clj" 208]
[build$uber invokeStatic "build.clj" 14]
[build$uber invoke "build.clj" 12]
[clojure.lang.AFn applyToHelper "AFn.java" 154]
[clojure.lang.AFn applyTo "AFn.java" 144]
[clojure.lang.Var applyTo "Var.java" 705]
[clojure.core$apply invokeStatic "core.clj" 667]
[clojure.core$apply invoke "core.clj" 662]
[clojure.run.exec$exec invokeStatic "exec.clj" 48]
[clojure.run.exec$exec doInvoke "exec.clj" 39]
[clojure.lang.RestFn invoke "RestFn.java" 423]
[clojure.run.exec$_main$fn__205 invoke "exec.clj" 180]
[clojure.run.exec$_main invokeStatic "exec.clj" 176]
[clojure.run.exec$_main doInvoke "exec.clj" 139]
[clojure.lang.RestFn applyTo "RestFn.java" 137]
[clojure.lang.Var applyTo "Var.java" 705]
[clojure.core$apply invokeStatic "core.clj" 667]
[clojure.main$main_opt invokeStatic "main.clj" 514]
[clojure.main$main_opt invoke "main.clj" 510]
[clojure.main$main invokeStatic "main.clj" 664]
[clojure.main$main doInvoke "main.clj" 616]
[clojure.lang.RestFn applyTo "RestFn.java" 137]
[clojure.lang.Var applyTo "Var.java" 705]
[clojure.main main "main.java" 40]],
:cause "No dispatch macro for: ?"}}

Commented: relative directories in classpath-roots

Wed, 22 Jun 2022 20:18:00 +0000

It does. I'll think about it.

Answer selected: Is it possible to set a var during compilation in tools.build?

Thu, 03 Mar 2022 10:26:10 +0000

Right, tools.build forks a new process to do the compilation and creates the compilation code, so there currently is no way to do this. But, might be something worth exploring and I made a ticket at https://clojure.atlassian.net/browse/TBUILD-28 (I would particularly interesting in finding a broader set of use cases before working on it though).

I think my best suggestion for a workaround is to not intertwine your tests with your code so you don't need to do this.

Commented: How to control the transient deps that get compiled/assembled into an uberjar?

Fri, 14 Jan 2022 00:28:09 +0000

The race condition on load here should be fixed in latest release of tools.build btw.

Closed: tools.build copy-dir with replace loses file permissions

Mon, 13 Dec 2021 04:12:41 +0000

When you use clojure.tools.build.api/copy-dir with :replace it reads the source file and then writes a new target file -- it doesn't "copy" the file so the target file is created with default permissions.

This is a problem if you are copying executable shell scripts and trying to replace text in them because the target file created won't have executable permissions.

This cropped up with deps-new in this issue: https://github.com/seancorfield/deps-new/issues/22

I think that if you source file is executable, the target file should also be executable -- and that works fine without :replace.

Closed: Allow specifying the output pom path

Sun, 12 Dec 2021 15:25:09 +0000

My initial use for tools.build is to update the pom.xml in the project with the appropriate version. It would be great if I could specify that write-pom should be output to pom.xml, rather than the folder layout that is imposed on me by the current function.

Retagged: tools.build/jar doesn't support "sections" in manifest

Mon, 06 Dec 2021 02:29:18 +0000

Sections are groups which start with Name: and have section-specific entries in them.

Capsule uses this for having platform-specific information about how to start.

Here's an example of using the API to get section information:

Main-Class: clojure.main

Name: Frank
Main-Class: frank.clojure.main

and

❯ clj       
Clojure 1.10.3
user=> (require '[clojure.java.io :as io])
nil
user=> (io/input-stream "/tmp/MANIFEST.MF")
#object[java.io.BufferedInputStream 0x69ce2f62 "java.io.BufferedInputStream@69ce2f62"]
user=> (def mf (java.util.jar.Manifest. (io/input-stream "/tmp/MANIFEST.MF")))
#'user/mf
user=> (.getAttributes mf "Frank")
{#object[java.util.jar.Attributes$Name 0x2e3a5237 "Main-Class"] "frank.clojure.main"}
user=> (.getMainAttributes mf)
{#object[java.util.jar.Attributes$Name 0x2e3a5237 "Main-Class"] "clojure.main"}
user=> (.getEntries mf)
{"Frank" {#object[java.util.jar.Attributes$Name 0x2e3a5237 "Main-Class"] "frank.clojure.main"}}

Answered: tools.build uber's default conflict handlers don't append to META-INF/services properly

Fri, 26 Nov 2021 18:04:13 +0000

Thanks, fixed in v0.6.8 d79ae84

Closed: Add git-branch function

Sat, 13 Nov 2021 00:04:15 +0000

This is useful for deciding whether to issue a SNAPSHOT release or not.

Here's a working implementation if anyone wants it for their project now:

(ns build
  (:require [clojure.string :as str]
            [clojure.tools.build.api :as b]
            [clojure.tools.build.api.specs :as specs]))

(defn git-branch
  "Shells out to git and returns the current branch
    git branch --show-current
  Options:
    :dir - dir to invoke this command from, by default current directory"
  [{:keys [dir] :or {dir "."} :as params}]
  (@#'b/assert-specs "git-branch" params :dir ::specs/path)
  (-> {:command-args ["git" "branch" "--show-current"]
       :dir (.getPath (b/resolve-path dir))
       :out :capture}
    b/process
    :out
    str/trim))

(def lib 'my-group/my-lib)

(def version
  (if (= "master" (git-branch nil))
    (format "1.0.%s" (b/git-count-revs nil))
    (format "1.0.%s-SNAPSHOT" (b/git-count-revs nil))))

Closed: Add git-hash function

Fri, 12 Nov 2021 23:58:46 +0000

I want api to get git hash to find the exact version.
Thank you.

(defn git-hash
  "Shells out to git and returns hash of commits on this branch:
    git rev-parse HEAD

  Options:
    :dir - dir to invoke this command from, by default current directory
    :short? - shorten hash to 7 length characters"
  [{:keys [dir short?] :or {dir "."} :as params}]
  (assert-specs "git-hash" params
                :dir ::specs/path
                :short? ::specs/boolean)
  (-> {:command-args (cond-> ["git" "rev-parse"]
                       short? (conj "--short")
                       :default (conj "HEAD"))
       :dir (.getPath (resolve-path dir))
       :out :capture}
      process
      :out
      str/trim))

Closed: tools.build's compile-clj does not allow setting jvm options

Fri, 12 Nov 2021 22:53:11 +0000

I've a project that uses Malli with a custom default registry, a feature which requires the code be compiled with a certain jvm opt set as is detailed in its documentation.

It was suggested to me in this issue that this is currently not supported in tools.build's compile-clj function. I'm posting here in the hopes this can be filed as a feature request so that I can eventually move this project to tools.build.

Thanks.

Commented: tools.build uber task fails when the dependency tree contains a dep which has no jar

Tue, 12 Oct 2021 16:00:46 +0000

Ok, this is fixed in tools.deps.alpha and in tools.build v0.6.2.

Comment edited: tools.build.api/copy-dir corrupts binary files if :replace is used

Mon, 11 Oct 2021 04:51:04 +0000

The :include option is about what files should be copied. In this case, you do (I presume) want the file copied, you just don't want it filtered, so this is a secondary level. I've added an option :non-replaced-exts in v0.6.1 for this that defaults to include a few common image types found in resources, including .png.

Commented: Should tools.build functions respect with-dir (from tools.deps.alpha)?

Thu, 09 Sep 2021 00:27:25 +0000

I'm tracking this for depstar in https://github.com/seancorfield/depstar/issues/101

Answered: getting an error with tools.build uberjar

Wed, 28 Jul 2021 21:20:23 +0000

Created ticket https://clojure.atlassian.net/browse/TBUILD-11

Answer selected: tools.build create-basis cannot use alias that includes tools.deps.alpha

Wed, 28 Jul 2021 20:24:37 +0000

Sorry, that resource was a temporary hack that was supposed to be removed and I've now deleted it for the next release of tools.build.

Closed: Add ability to customize JAR manifest created by clojure.tools.build.api/uber

Tue, 20 Jul 2021 18:35:51 +0000

There are several reasons we need to customize the META-INF/MANIFEST.MF file created by clojure.tools.build.api/uber:

A Java library we use, Liquibase, requires a Liquibase-Package entry in the manifest file to be used inside uberjars
We'd like to exclude Multi-Release: true from the built uberjar even tho some of our libs our multi-release. Log4j is an order of magnitude slower in a multi-release JAR and until we figure out how to fix that issue we've just been creating single-release JARs

With Leiningen you can specify the contents of the manifest by including a :manifest key in project.clj... adding an option like that to tools.build would be extremely helpful.

Answer selected: What does "Manifest type :jar not loaded when finding deps ..." mean?

Sun, 18 Jul 2021 17:41:11 +0000

This is a bug in the latest prerelease and I have fixed it for the next release.

Answered: Exclude existing META-INF/MANIFEST.MF when invoking clojure.tools.build.api/uber

Tue, 13 Jul 2021 23:38:42 +0000

depstar has drop-in replacements for tools.build's jar and uber functions that handle merging of LICENSE files, a bunch more exclusions, merging log4j2 plugin caches, etc. See https://github.com/seancorfield/depstar/blob/develop/src/hf/depstar/api.clj

Right now you'd have to depend on HEAD via :git/url as I'm reworking all the documentation before I cut the next release, but I'd be interested in feedback if you're willing to try it out.

See the example https://github.com/seancorfield/depstar/blob/develop/build.clj which is the tools.build examples with depstar's versions of jar and uber swapped in.