如何在Jenkins文件中加入两个值？

Question

**我试图通过下面的jenkins文件语法来串联两个值。也许，我无法做到。

输出值 + Jenkins构建编号应保存在新变量**

连接的控制台输出 /日志中以供参考。寻找此问题声明的输入 /建议。

pipeline {
    agent any
    environment {
        AWS_ACCOUNT_ID="xyz"
        AWS_DEFAULT_REGION="xyz" 
        IMAGE_REPO_NAME="abc/xyz"
        REPOSITORY_URI = "${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_DEFAULT_REGION}.amazonaws.com/${IMAGE_REPO_NAME}"
        BLD_NUMBER = "${env.BUILD_NUMBER}"

    }
   
    stages {
        
         stage('Logging into AWS ECR') {
            steps {
                script {
                sh "aws ecr get-login-password --region ${AWS_DEFAULT_REGION} | docker login --username AWS --password-stdin ${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_DEFAULT_REGION}.amazonaws.com"
                }
            }
        }

        stage('Build Release') {          
            steps {
                script {
                    def version = sh script: 'mvn help:evaluate -Dexpression=project.version -q -DforceStdout', returnStdout: true
                    sh "echo version value is $version"
                    def pom_toupdate = sh script: "echo ${version} | rev | cut -c2- | rev", returnStdout: true
                    sh "echo pom_toupdate version is $pom_toupdate"
                    def newpomversion = sh script: "echo ${pom_toupdate} + ${BLD_NUMBER}", returnStdout: true
                    sh "echo newpomversion value is $newpomversion"
            }

        }
    }
}

output_error / logs：

Login Succeeded
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Build Release)
[Pipeline] script
[Pipeline] {
[Pipeline] sh
+ mvn help:evaluate -Dexpression=project.version -q -DforceStdout
[Pipeline] sh
+ echo version value is 4.51.0
version value is 4.51.0
[Pipeline] sh
+ rev
+ cut -c2-
+ rev
+ echo 4.51.0
[Pipeline] sh
+ echo pom_toupdate version is 4.51.
pom_toupdate version is 4.51.
[Pipeline] sh
+ echo 4.51.
+ 195
/var/lib/jenkins/workspace/xxx@tmp/durable-d0262401/script.sh: line 2: 195: command not found
4.51.
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code 127
Finished: FAILURE

desired_output：

newpomversion should have 4.51.195