executable not found on docker container

I'm having some issue trying to run a CMD command inside a docker container with a Go application.

This is the output I've got:

golang-api | /bin/sh: ./server: not found
golang-api exited with code 127

This is the Dockerfile

FROM golang:1.18-alpine

RUN apk add g++ && apk add make

WORKDIR /app

COPY go.mod go.sum ./

RUN go mod download

COPY . .

RUN make build

EXPOSE 8000

CMD ./server

And this is the Makefile responsible for the build command:

LINUX_AMD64 = GOOS=linux GOARCH=amd64 CGO_ENABLED=1 GO111MODULE=on

migrate:
	cd cmd/migrations/$(FOLDER) && go run main.go

build:
	cd cmd && $(LINUX_AMD64) go build -a -v -tags musl -o server

And the docker-compose.yml

version: '3.1'

services:
  api:
    build:
      dockerfile: Dockerfile
      context: .
    container_name: golang-api
    ports:
      - "8000:8000"
    restart: unless-stopped
    depends_on:
      - db
    environment:
      - POSTGRES_URL=$POSTGRES_URL

  db:
    image: postgres
    restart: always
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    ports:
      - '5432:5432'

Complete output:

Building api
Sending build context to Docker daemon  74.24kB
Step 1/9 : FROM golang:1.18-alpine
 ---> 6078a5fce1f5
Step 2/9 : RUN apk add g++ && apk add make
 ---> Using cache
 ---> 2a85b9182b80
Step 3/9 : WORKDIR /app
 ---> Using cache
 ---> baf1e6b7047c
Step 4/9 : COPY go.mod go.sum ./
 ---> Using cache
 ---> 1f2d031bc1b0
Step 5/9 : RUN go mod download
 ---> Using cache
 ---> 471d6f24e6a9
Step 6/9 : COPY . .
 ---> eaa86ff7cb1b
Step 7/9 : RUN make build
 ---> Running in d6ae6ce79222
cd cmd && GOOS=linux GOARCH=amd64 CGO_ENABLED=1 GO111MODULE=on go build -a -v -tags musl -o server
internal/goos
internal/goarch
internal/race
internal/unsafeheader
internal/goexperiment
runtime/internal/syscall
internal/cpu
sync/atomic
runtime/internal/atomic
internal/itoa
math/bits
internal/abi
runtime/internal/math
runtime/internal/sys
unicode/utf8
unicode
container/list
crypto/internal/subtle
crypto/subtle
unicode/utf16
vendor/golang.org/x/crypto/cryptobyte/asn1
internal/nettrace
vendor/golang.org/x/crypto/internal/subtle
encoding
github.com/mymachine/my-api/internal/controllers/dto
github.com/mymachine/my-api/internal/controllers/helpers
internal/bytealg
math
runtime
internal/reflectlite
sync
internal/testlog
internal/singleflight
math/rand
runtime/cgo
errors
sort
internal/oserror
strconv
path
vendor/golang.org/x/net/dns/dnsmessage
io
crypto/elliptic/internal/fiat
syscall
golang.org/x/text/internal/tag
hash
bytes
strings
hash/crc32
reflect
crypto
crypto/internal/randutil
crypto/hmac
crypto/rc4
net/http/internal/ascii
vendor/golang.org/x/crypto/hkdf
regexp/syntax
github.com/jackc/chunkreader/v2
bufio
crypto/elliptic/internal/nistec
internal/syscall/unix
time
internal/syscall/execenv
vendor/golang.org/x/text/transform
golang.org/x/crypto/pbkdf2
golang.org/x/text/transform
golang.org/x/text/runes
golang.org/x/text/width
regexp
internal/poll
io/fs
context
github.com/mymachine/my-api/internal/entities
github.com/jackc/pgconn/internal/ctxwatch
embed
os
github.com/jinzhu/inflection
github.com/jinzhu/now
internal/fmtsort
encoding/binary
crypto/ed25519/internal/edwards25519/field
crypto/md5
crypto/sha512
crypto/cipher
crypto/sha256
crypto/sha1
encoding/base64
fmt
internal/godebug
encoding/pem
crypto/ed25519/internal/edwards25519
path/filepath
vendor/golang.org/x/crypto/internal/poly1305
io/ioutil
internal/intern
vendor/golang.org/x/crypto/curve25519/internal/field
vendor/golang.org/x/sys/cpu
net/netip
crypto/aes
crypto/des
vendor/golang.org/x/crypto/chacha20
github.com/jackc/pgio
github.com/jackc/pgpassfile
os/exec
os/signal
net
vendor/golang.org/x/crypto/chacha20poly1305
math/big
encoding/hex
net/url
compress/flate
vendor/golang.org/x/crypto/curve25519
log
vendor/golang.org/x/text/unicode/norm
vendor/golang.org/x/text/unicode/bidi
vendor/golang.org/x/net/http2/hpack
mime
mime/quotedprintable
compress/gzip
net/http/internal
database/sql/driver
github.com/mymachine/my-api/internal/pkg/errors
encoding/json
github.com/jackc/pgservicefile
vendor/golang.org/x/text/secure/bidirule
golang.org/x/text/internal/language
database/sql
golang.org/x/text/unicode/norm
golang.org/x/text/unicode/bidi
vendor/golang.org/x/net/idna
os/user
crypto/rand
encoding/asn1
crypto/dsa
crypto/elliptic
crypto/ed25519
crypto/rsa
github.com/jackc/pgproto3/v2
golang.org/x/text/internal/language/compact
golang.org/x/text/secure/bidirule
github.com/jackc/pgx/v4/internal/sanitize
golang.org/x/text/language
go/token
vendor/golang.org/x/crypto/cryptobyte
crypto/x509/pkix
gorm.io/gorm/utils
gorm.io/gorm/logger
encoding/gob
go/scanner
golang.org/x/text/internal
github.com/joho/godotenv
crypto/ecdsa
go/ast
golang.org/x/text/cases
github.com/joho/godotenv/autoload
golang.org/x/text/secure/precis
gorm.io/gorm/clause
gorm.io/gorm/schema
gorm.io/gorm
net/textproto
vendor/golang.org/x/net/http/httpproxy
github.com/google/uuid
crypto/x509
github.com/jackc/pgtype
mime/multipart
vendor/golang.org/x/net/http/httpguts
crypto/tls
gorm.io/gorm/migrator
gorm.io/gorm/callbacks
net/http/httptrace
github.com/jackc/pgconn
net/http
github.com/jackc/pgconn/stmtcache
github.com/jackc/pgx/v4
github.com/jackc/pgx/v4/stdlib
gorm.io/driver/postgres
github.com/mymachine/my-api/internal/infrastructure/repository
github.com/mymachine/my-api/configs
github.com/mymachine/my-api/internal/services
github.com/mymachine/my-api/internal/services/transaction
github.com/mymachine/my-api/internal/controllers/handlers/health
github.com/gorilla/mux
github.com/mymachine/my-api/internal/controllers/handlers/transaction
github.com/mymachine/my-api/internal/router
github.com/mymachine/my-api/cmd
Removing intermediate container d6ae6ce79222
 ---> 621aa6a266de
Step 8/9 : EXPOSE 8000
 ---> Running in 3cbd17d32c37
Removing intermediate container 3cbd17d32c37
 ---> 754f71a7753e
Step 9/9 : CMD ./server
 ---> Running in dfcdc8cd45ce
Removing intermediate container dfcdc8cd45ce
 ---> 511dbf89a001
Successfully built 511dbf89a001
Successfully tagged my-api_api:latest
Creating my-api_db_1 ... done
Creating golang-api            ... done
Attaching to my-api_db_1, golang-api
golang-api | /bin/sh: ./server: not found

The problem was solved.

Somehow,the RUN cd cmd command seemed not generating the file in the expected directory.

Trying with RUN go build cmd/main.go instead of using the makefile worked, as well pointed by @paltaa in the comments.