我刚刚在VirtualBox上安装了一个新的Ubuntu副本来试用Clojure。我按照说明@ https://clojure.org/guides/getting_started，安装了所有deps等，但是当我尝试使用clj运行repl时，我不断收到以下错误：
Error building classpath. Failed to read artifact descriptor for org.clojure:clojure:jar:1.9.0
org.eclipse.aether.resolution.ArtifactDescriptorException: Failed to read artifact descriptor for org.clojure:clojure:jar:1.9.0
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:276)
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.readArtifactDescriptor(DefaultArtifactDescriptorReader.java:192)
at org.eclipse.aether.internal.impl.DefaultRepositorySystem.readArtifactDescriptor(DefaultRepositorySystem.java:253)
at clojure.tools.deps.alpha.extensions.maven$eval685$fn__687.invoke(maven.clj:79)
at clojure.lang.MultiFn.invoke(MultiFn.java:243)
at clojure.tools.deps.alpha$expand_deps.invokeStatic(alpha.clj:170)
at clojure.tools.deps.alpha$expand_deps.invoke(alpha.clj:152)
at clojure.tools.deps.alpha$resolve_deps.invokeStatic(alpha.clj:215)
at clojure.tools.deps.alpha$resolve_deps.invoke(alpha.clj:197)
at clojure.tools.deps.alpha.script.make_classpath$create_classpath.invokeStatic(make_classpath.clj:59)
at clojure.tools.deps.alpha.script.make_classpath$create_classpath.invoke(make_classpath.clj:52)
at clojure.tools.deps.alpha.script.make_classpath$run.invokeStatic(make_classpath.clj:70)
at clojure.tools.deps.alpha.script.make_classpath$run.invoke(make_classpath.clj:64)
at clojure.tools.deps.alpha.script.make_classpath$_main.invokeStatic(make_classpath.clj:109)
at clojure.tools.deps.alpha.script.make_classpath$_main.doInvoke(make_classpath.clj:84)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.lang.Var.applyTo(Var.java:702)
at clojure.core$apply.invokeStatic(core.clj:657)
at clojure.main$main_opt.invokeStatic(main.clj:317)
at clojure.main$main_opt.invoke(main.clj:313)
at clojure.main$main.invokeStatic(main.clj:424)
at clojure.main$main.doInvoke(main.clj:387)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.lang.Var.applyTo(Var.java:702)
at clojure.main.main(main.java:37)
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Could not transfer artifact org.clojure:clojure:pom:1.9.0 from/to central (https://repo1.maven.org/maven2/): java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:422)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:224)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifact(DefaultArtifactResolver.java:201)
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:261)
... 24 more
Caused by: org.eclipse.aether.transfer.ArtifactTransferException: Could not transfer artifact org.clojure:clojure:pom:1.9.0 from/to central (https://repo1.maven.org/maven2/): java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at org.eclipse.aether.connector.basic.ArtifactTransportListener.transferFailed(ArtifactTransportListener.java:52)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$TaskRunner.run(BasicRepositoryConnector.java:365)
at org.eclipse.aether.util.concurrency.RunnableErrorForwarder$1.run(RunnableErrorForwarder.java:75)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$DirectExecutor.execute(BasicRepositoryConnector.java:583)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector.get(BasicRepositoryConnector.java:259)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.performDownloads(DefaultArtifactResolver.java:498)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:399)
... 27 more
Caused by: javax.net.ssl.SSLException: java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1964)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1921)
at sun.security.ssl.SSLSocketImpl.handleException(SSLSocketImpl.java:1904)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1420)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397)
at org.apache.http.conn.ssl.SSLSocketFactory.createLayeredSocket(SSLSocketFactory.java:573)
at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:557)
at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:414)
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180)
at org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:326)
at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:610)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:445)
at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:835)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:72)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
at org.apache.http.impl.client.DecompressingHttpClient.execute(DecompressingHttpClient.java:164)
at org.eclipse.aether.transport.http.HttpTransporter.execute(HttpTransporter.java:296)
at org.eclipse.aether.transport.http.HttpTransporter.implGet(HttpTransporter.java:252)
at org.eclipse.aether.spi.connector.transport.AbstractTransporter.get(AbstractTransporter.java:67)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$GetTaskRunner.runTask(BasicRepositoryConnector.java:453)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$TaskRunner.run(BasicRepositoryConnector.java:360)
... 32 more
Caused by: java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at sun.security.validator.PKIXValidator.<init>(PKIXValidator.java:91)
at sun.security.validator.Validator.getInstance(Validator.java:179)
at sun.security.ssl.X509TrustManagerImpl.getValidator(X509TrustManagerImpl.java:312)
at sun.security.ssl.X509TrustManagerImpl.checkTrustedInit(X509TrustManagerImpl.java:171)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:184)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1596)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1052)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:987)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1072)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413)
... 49 more
Caused by: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at java.security.cert.PKIXParameters.setTrustAnchors(PKIXParameters.java:200)
at java.security.cert.PKIXParameters.<init>(PKIXParameters.java:120)
at java.security.cert.PKIXBuilderParameters.<init>(PKIXBuilderParameters.java:104)
at sun.security.validator.PKIXValidator.<init>(PKIXValidator.java:89)
... 61 more
这是由于 Ubuntu 中的 java 证书错误，解决方案在以下 SO 帖子中：
ubuntu 15.10 和 openjdk-8-jdk 中是否缺少 cacerts 文件？