更改 observables 时，subscribe 内的 Observable 值未定义

我有一个来自某个库的函数，它返回一个我想从另一个函数调用的 Observable。我需要将该 Observable 传播到多个函数调用中。这是我的代码的结构：

extractSignature = (xml, signatureCount = 1) => {
    const observ = this.generateDigest(signedContent, alg).pipe(map(digest => {
            const sigContainer = {
                alg: alg,
                signature: signatureValue,
                signedContent: signedContent,
                digest: digest
            };
            console.log('sigContainer inside pipe: ');
            console.log(sigContainer);
            return sigContainer;
        }));

        return observ;
}

dissasemble(xml): Observable<SignatureContainerModel[]> {
    const observables: Observable<any>[] = [];
        for (let i = 1; i <= count; i++) {
            const extractSigObservable = this.extractSignature(xml, i);

            console.log('extractSigObs inside pipe: ');
            console.log(extractSigObservable);

            const observ = extractSigObservable.pipe(map(sigContainer => {
                console.log('sigContainer inside pipe: ');
                console.log(sigContainer);

                const hashContainers: HashContainerModel[] = [];
                const hashContainer: HashContainerModel = new HashContainerModel();
                hashContainer.digestAlgorithm = sigContainer.alg;
                hashContainer.bytes = sigContainer.digest;
                hashContainers.push(hashContainer);
                const signatureContainer: SignatureContainerModel = {
                    hashContainers: hashContainers,
                    signature: sigContainer.signature
                };

                console.log('observable inside pipe: ');
                console.log(observ);
            }));


            observables.push(observ);
        }

        return forkJoin(observables);
}

verify() {
    this.sigExec.dissasemble(this.fileContent).subscribe((signatureContainers: SignatureContainerModel[]) => {
                // signatureContainers is [undefined] here
                console.log('Sig Containers: ');
                console.log(signatureContainers);
                this.verifyHash(signatureContainers);
            });
}

signatureContainers变量在订阅中是 [undefined]。我不确定问题是什么，因为当我检查我在 map 函数中写的所有日志时，它们看起来很好