tools.build normally expects the build.clj file in the root of the project, although I think src should work too. do you have (ns build ...) in the file?

hello, yes . I´ll change it to root of project and try again

it seems that in src it´ll not work.

maybe add :extra-paths ["src"] to the build alias

if you really want to have it under src

no, I´m not

As mentioned above, running a tool with -T removes the project :paths and :deps. Using -T:build will use only the :paths and :deps from the :build alias. The root deps.edn is still included, which will pull in Clojure as well (but it would also come in as a dependency of tools.build). The :paths are not specified here, so no additional paths are added, however, -T includes the project root "." as a path by default.

So executing clj -T:build jar will use an effective classpath here of:

"."

clojure (from the root deps.edn)

tools.build (from the :build alias :deps)

the transitive dependencies needed by clojure and tools.build

https://clojure.org/guides/tools_build

Yes, that because I use

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

(def lib 'mylib/lib)
(def version (format "1.2.%s" (b/git-count-revs nil)))
(def class-dir "target/classes")
(def basis (b/create-basis {:project "deps.edn"}))
(def uber-file (format "target/%s-%s-standalone.jar" (name lib) version))

(defn clean [_]
  (b/delete {:path "target"}))

(defn uber [_]
  (clean nil)
  (b/copy-dir {:src-dirs ["src" "resources"]
               :target-dir class-dir})
  (b/compile-clj {:basis basis
                  :src-dirs ["src"]
                  :class-dir class-dir})
  (b/uber {:class-dir class-dir
           :uber-file uber-file
           :basis basis
           :main 'mylib.core}))

Good luck, the explanation is above in the documentation :)

thank you for your time